Communications system and method, wireless communications system, wireless microphone and wireless receiver

ABSTRACT

Herein disclosed a communications system according to the present invention comprises, a wireless microphone transmission apparatus for transmitting a radio microphone signal on a predetermined wireless microphone frequency channel carrying a voice signal and a tone signal; and a wireless receiving apparatus for receiving the radio microphone signal on the predetermined wireless microphone frequency channel carrying the voice signal and the tone signal transmitted by the wireless microphone transmission apparatus. The wireless receiving apparatus includes an integral computing unit for sequentially computing integrals of the signal levels of the tones of the tone signal at first predetermined time intervals and a data information computing unit for sequentially computing differences between two respective integrals of the signal levels of the tones of the tone signal, at respective second predetermined time intervals to acquire data information.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a communications system fortransmitting and receiving a voice signal and a tone signal, and moreparticularly, to a communications system, a communication method, awireless communications system, a wireless microphone, and a wirelessreceiver for transmitting and receiving a voice signal and a tonesignal.

[0003] 2. Description of the Related Art

[0004] There have been proposed a wide variety of wirelesscommunications systems each comprising a wireless microphonetransmission apparatus for inputting a voice therethrough, convertingthe voice into a voice signal, modulating the voice signal with acarrier signal to generate a radio microphone signal, and transmittingthe radio microphone signal carrying the voice signal, and a wirelessreceiving apparatus for receiving the radio microphone signal carryingthe voice signal transmitted by the wireless microphone transmissionapparatus, demodulating the radio microphone signal to generate thevoice signal, converting the voice signal into the voice, and outputtingthe voice therethrough, thereby omitting a cable connecting between thewireless microphone transmission apparatus and the wireless receivingapparatus.

[0005] In such a wireless communications system, the wireless receivingapparatus is provided with a squelch circuit which is operative to cutoff the operation of outputting the voice if the signal level of thereceived voice signal falls too low or the signal level of the noisesignal increases too high, thereby avoiding a situation where high noisesignals are outputted in the absence of wanted voice signals. Theoperation of the squelch circuit for cutting off the operation ofoutputting the voice if the level of the received voice signal falls toolow or the level of the noise signal is too high will be hereinlaterreferred to as a “squelch operation”. The wireless communications systemcontrols the squelch circuit to avoid outputting high noise signals whenthe wireless microphone transmission apparatus is turned off and nottransmitting any voice signal.

[0006] The radio microphone signal transmitted by the wirelessmicrophone transmission apparatus may include a noise signal, a carriersignal, and a tone signal. The squelch circuit includes various typessuch as a noise squelch circuit for performing the squelch operation onthe basis of the noise signal contained in the received radio microphonesignal, a carrier squelch circuit for performing the squelch operationon the basis of the carrier component contained in the received radiomicrophone signal, and a tone squelch circuit for performing the squelchoperation on the basis of the tone signal contained in the receivedradio microphone signal.

[0007] The noise squelch circuit and the carrier squelch circuitencounters drawbacks being inclined to operate malfunctions due to thefact that they are vulnerable to misidentifying noises unnecessarilyemitted from electrical appliances such as a personal computer, apachinko machine and an air cleaning device. The wireless receivingapparatus is therefore equipped with the tone squelch circuit inaddition to the noise squelch circuit or the carrier squelch circuit toprevent from performing malfunctions caused by the noises emitted fromthe electrical appliances.

[0008] The wireless microphone transmission apparatus is designedneither to transmit any tone signal until a predetermined time elapsesafter the turn-on operation of the wireless microphone transmissionapparatus, nor to turn off the power until a predetermined time elapsesafter the turn-off operation of the power switch, in order to cut offnoises occurred when the wireless microphone transmission apparatus isturned on and off.

[0009] Referring to FIGS. 21, 22, and 23 of the drawings, there is showna conventional wireless communications system 700 of this typecomprising a conventional wireless microphone transmission apparatus 710and a conventional wireless receiving apparatus 740. In thisconventional wireless communications system 700, the conventionalwireless microphone transmission apparatus 710 is adapted to transmit atone signal when the wireless microphone transmission apparatus 710 isturned on. The conventional wireless receiving apparatus 740 is equippedwith a squelch circuit section 727 operative not to output a voicesignal when no tone signal is received from the conventional wirelessmicrophone transmission apparatus 710.

[0010] The conventional wireless microphone transmission apparatus 710is shown in FIG. 21 as comprising a voice inputting section 701 forinputting a voice information therethrough and converting the voiceinformation into a voice signal, a tone signal generating section 702for generating a tone signal, a mixing section 703 for mixing the voicesignal and the tone signal to generate a transmission signal, anoscillation section 704 for generating a carrier signal, a modulatingsection 705 for modulating the transmission signal with the carriersignal, a high-frequency amplifying section 706 for amplifying themodulated transmission signal to generate a radio microphone signal on aparticular microphone frequency channel, and a transmission antenna 707for transmitting the radio microphone signal on the particularmicrophone frequency channel to the conventional wireless receivingapparatus 740.

[0011] The conventional wireless receiving apparatus 740 is shown inFIG. 22 as comprising a receiving antenna 721 for receiving radiomicrophone signals, a high-frequency amplifying section 722 foramplifying the received radio microphone signals, a frequency conversionsection 723 for selecting a radio microphone signal on the particularmicrophone frequency channel from among the radio microphone signals andconverting the selected radio microphone signal on the particularmicrophone frequency channel into a intermediate-frequency microphonesignal, an intermediate-frequency amplifying section 724 for amplifyingthe intermediate-frequency microphone signal, a decoding section 725 forgenerating a microphone signal from the intermediate-frequencymicrophone signal thus amplified, a band pass filter (referred to as“BPF”) 726 for filtering the voice signal therethrough from themicrophone signal inputted by the decoding section 725, a squelchcircuit section 727 for cutting off or passing through the voice signalinputted from band pass filter 726, a low-frequency amplifying section728 for amplifying the voice signal, a crystal filter 729 for filteringthe tone signal therethrough from the microphone signal inputted by thedecoding section 725, and a squelch circuit control section 730 forcontrolling the squelch circuit section 727 to have the voice signal cutoff or pass through on the basis of the tone signal inputted from thecrystal filter 729. The conventional wireless receiving apparatus 740thus constructed can extract the voice signal and tone signal from thereceived radio microphone signal to output the voice signal and tonesignal separately.

[0012] In the conventional wireless receiving apparatus 740 thusconstructed, the squelch circuit control section 730 is operative tocontrol the squelch circuit section 727 so as to output the voice signalonly when the tone signal is filtered through by the crystal filter 729.Otherwise, the squelch circuit control section 730 is operative to cutoff the electrical connection between the BPF 726 and the low-frequencyamplifying section 728 to prevent any noise signal from being outputted.

[0013]FIG. 23 is a graph showing an example of a transmission signal,i.e., a radio microphone signal including a voice signal and a tonesignal transmitted and received in the conventional wirelesscommunications system 700. As will be understood from FIG. 23, thefrequency of the tone signal is generally chosen outside of thefrequency range of the voice signal.

[0014] The wireless communications system is recently utilized in anoccasion of making a presentation. During the presentation, a presenteris required to control operations of various devices such as, forexample, the sound level of the wireless receiving apparatus whichreceives and amplifies the presenter's voice, the operation of therecording apparatus which records the presenter's presentation, andreplaying and adjusting operations of the video tape recorder. Thus, thepresenter tends to utilize the wireless communications system not onlyfor amplifying the presenter's voice but also for controlling theoperations of the other devices. Some types of the wirelesscommunications system use the tone signal for conveying control data inorder to control the operations of various devices.

[0015] Such types of wireless communications system include two typesconsisting of a first type of wireless communications system foramplitude-modulating a tone signal to convey a control data, and asecond type wireless communications system for generating a tone signalhaving a plurality of tones each having a signal level and repeated atpredetermined time intervals to convey a control data. The wirelesscommunications system of the second type is disclosed, for example, inJapanese Patent Laid-open Publication No. 6-113376 as comprising awireless microphone transmission apparatus including a tone generatingsection for generating a tone signal having a plurality of tonesrepeated at predetermined time intervals and a wireless receivingapparatus. “A tone signal” is intended to mean “a plurality of toneshaving a signal level” oscillated or repeated at “time intervals”. Thewireless microphone transmission apparatus disclosed therein is adaptedto transmit a radio microphone signal carrying a tone signal indicativeof a control data having a plurality of tones repeated at predeterminedtime intervals, and the wireless receiving apparatus disclosed thereinis adapted to receive the radio microphone signal to extract the tonesignal and detect the control data, thereby making it possible for thewireless communications system to have a tone signal transmitted andreceived.

[0016] The above wireless communications system, however encounters adrawback that the squelch circuit may cut off the wanted voice when notone signal happens to be detected for a certain time interval as aresult of an incidental combination of tone signals.

[0017] The above wireless communications system encounters anotherdrawback that the wireless receiving apparatus of the above system isrequired to include one extraction circuit for extracting one type oftone signal having tones repeated at predetermined time intervals. Thismeans that the wireless receiving apparatus of the above system isrequired to include two extraction circuits for extracting two types oftone signals each having tones repeated at respective predetermined timeinterval. This leads to the fact that the wireless receiving apparatusof the above system is required to include the same number of extractioncircuits as the number of types of tone signals each having tonesrepeated at respective predetermined time interval.

[0018] Furthermore, the above wireless communications system encountersanother drawback that the sensitivity is deteriorated and thetransmission distance is shortened because the signal to noise ratio,i.e., SN ratio is worsened whenever the tone signals areamplitude-modulated.

SUMMARY OF THE INVENTION

[0019] It is therefore a primary object of the present invention toprovide a communications system which realizes a high reliability, ahigh sensitivity, and a long transmission distance.

[0020] It is another object of the present invention to provide acommunication method which realizes a high reliability, a highsensitivity, and a long transmission distance.

[0021] It is a further object of the present invention to provide awireless communications system which realizes a high reliability, a highsensitivity, and a long transmission distance.

[0022] It is a still further object of the present invention to providea wireless microphone transmission apparatus which realizes a highreliability, a high sensitivity, and a long transmission distance.

[0023] It is a yet still further object of the present invention toprovide a wireless receiving apparatus which realizes a highreliability, a high sensitivity, and a long transmission distance.

[0024] In accordance with a first aspect of the present invention, thereis provided a communications system for transmitting and receiving acarrier communication signal carrying a voice signal indicative of voiceinformation and a tone signal indicative of data information,comprising: transmission means for transmitting the carriercommunication signal carrying the voice signal and the tone signal; andreceiving means for receiving the carrier communication signal carryingthe voice signal and the tone signal transmitted by the transmissionmeans, the transmission means including: a voice inputting unit forinputting the voice information therethrough to generate the voicesignal indicative of the voice information; a data inputting unit forinputting the data information therethrough; a tone signal generatingunit for generating the tone signal indicative of the data informationon the basis of the data information inputted by the data inputtingunit, the tone signal having a plurality of tones each having a signallevel and repeated at predetermined time intervals; a mixing unit formixing the voice signal generated by the voice inputting unit and thetone signal generated by the tone signal generating unit to generate acommunication signal carrying the voice signal and the tone signal; amodulating unit for modulating the communication signal carrying thevoice signal and the tone signal generated by the mixing unit with acarrier signal to generate a carrier communication signal carrying thevoice signal and the tone signal; a transmission unit for transmittingthe carrier communication signal carrying the voice signal indicative ofthe voice information and the tone signal indicative of the datainformation modulated by the modulating unit, therethrough, and thereceiving means including: a receiving unit for receiving the carriercommunication signal carrying the voice signal indicative of the voiceinformation and the tone signal indicative of the data informationtransmitted by the transmission means; a demodulating unit fordemodulating the carrier communication signal carrying the voiceinformation and the tone signal received by the receiving unit togenerate the communication signal; a voice signal filtering unit forfiltering the voice signal indicative of the voice informationtherethrough from the communication signal generated by the demodulatingunit; a tone signal filtering unit for filtering the tone signaltherethrough from the communication signal generated by the demodulatingunit; an integral computing unit for sequentially computing integrals ofthe signal levels of the tones of the tone signal passed through by thetone signal filtering unit, at first predetermined time intervals; adata information computing unit for sequentially computing differencesbetween two respective integrals of the signal levels of the tones ofthe tone signal computed by the integral computing unit, at respectivesecond predetermined time intervals each starting at a leading point andending at a trailing point to acquire the data information on the basisof the differences; a data information outputting unit for outputtingthe data information acquired by the data information computing unit,therethrough; and a voice information outputting unit for outputting thevoice information on the basis of the voice signal filtered through bythe voice signal filtering unit, therethrough, in accordance with thedata information outputted by the data information outputting unit.

[0025] In the aforesaid communications system, the data informationcomputing unit of the receiving means may be operative to judge whetherthe integrals of the signal levels of the tones of the tone signalcomputed by the integral computing unit are in a predetermineddetectable range, and if the data information computing unit judges thatthe integrals of the signal levels of the tones of the tone signal arenot in the predetermined detectable range, the data informationcomputing unit is operative to instruct the integral computing unit ofthe receiving means to compensate the integrals thus computed so thatthe integrals thus compensated are in the predetermined detectablerange, and the data information computing unit is operative tosequentially compute differences between two respective integrals of thesignal levels of the tones of the tone signal compensated by theintegral computing unit, at respective second predetermined timeintervals each starting at a leading point and ending at a trailingpoint to acquire the data information on the basis of the differences.

[0026] In accordance with a second aspect of the present invention,there is provided a communication method for transmitting and receivinga carrier communication signal carrying a voice signal indicative ofvoice information and a tone signal indicative of data information,comprising the steps of: (a) transmitting the carrier communicationsignal carrying the voice signal and the tone signal; and (b) receivingthe carrier communication signal carrying the voice signal and the tonesignal transmitted in the step (a), the step (a) including the steps of:(a1) inputting the voice information therethrough to generate the voicesignal indicative of the voice information; (a2) inputting the datainformation therethrough; (a3) generating the tone signal indicative ofthe data information on the basis of the data information inputted inthe step (a2), the tone signal having a plurality of tones each having asignal level and repeated at predetermined time intervals; (a4) mixingthe voice signal generated in the step (a1) and the tone signalgenerated by the step (a3) to generate a communication signal carryingthe voice signal and the tone signal; (a5) modulating the communicationsignal carrying the voice signal and the tone signal generated in thestep (a4) with a carrier signal to generate a carrier communicationsignal carrying the voice signal and the tone signal; (a6) transmittingthe carrier communication signal carrying the voice signal indicative ofthe voice information and the tone signal indicative of the datainformation modulated in the step (a5), therethrough, and the step (b)including the steps of: (b1) receiving the carrier communication signalcarrying the voice signal indicative of the voice information and thetone signal indicative of the data information transmitted in the step(a); (b2) demodulating the carrier communication signal carrying thevoice information and the tone signal received in the step (b1) togenerate the communication signal; (b3) filtering the voice signalindicative of the voice information therethrough from the communicationsignal generated in the step (b2); (b4) filtering the tone signaltherethrough from the communication signal generated in the step (b2);(b5) sequentially computing integrals of the signal levels of the tonesof the tone signal passed through in the step (b4), at firstpredetermined time intervals; (b6) sequentially computing differencesbetween two respective integrals of the signal levels of the tones ofthe tone signal computed in the step (b5), at respective secondpredetermined time intervals each starting at a leading point and endingat a trailing point to acquire the data information on the basis of thedifferences; (b7) outputting the data information acquired by the step(b6), therethrough; and (b8) outputting the voice information on thebasis of the voice signal filtered through in the step (b3),therethrough, in accordance with the data information outputted in thestep (b7).

[0027] In the aforesaid communication method, the step (b6) may have thestep of (b61) judging whether the integrals of the signal levels of thetones of the tone signal computed by the (b5) are in a predetermineddetectable range, and if it is judged that the integrals of the signallevels of the tones of the tone signal are not in the predetermineddetectable range in the step (b61), the step (b5) has the step of (b51)compensating the integrals thus computed so that the integrals thuscompensated are in the predetermined detectable range, and the step (b6)has the step of (b62) sequentially compute differences between tworespective integrals of the signal levels of the tones of the tonesignal compensated by the (b51), at respective second predetermined timeintervals each starting at a leading point and ending at a trailingpoint to acquire the data information on the basis of the differences.

[0028] In accordance with a third aspect of the present invention, thereis provided a wireless communications system for transmitting andreceiving a radio microphone signal carrying a voice signal indicativeof voice information and a tone signal indicative of data information,comprising: at least one wireless microphone transmission apparatus fortransmitting the radio microphone signal on a predetermined wirelessmicrophone frequency channel carrying the voice signal and the tonesignal; and one wireless receiving apparatus for receiving the radiomicrophone signal on the predetermined wireless microphone frequencychannel carrying the voice signal and the tone signal transmitted by thewireless microphone transmission apparatus, the wireless microphonefrequency channel allocated to each of the wireless microphonetransmission apparatuses and the wireless receiving apparatus; thewireless microphone transmission apparatus including: a voice inputtingunit for inputting the voice information therethrough to generate thevoice signal indicative of the voice information; a data inputting unitfor inputting the data information therethrough; a tone signalgenerating unit for generating the tone signal indicative of the datainformation on the basis of the data information inputted by the datainputting unit, the tone signal having a plurality of tones each havinga signal level and repeated at predetermined time intervals; a mixingunit for mixing the voice signal generated by the voice inputting unitand the tone signal generated by the tone signal generating unit togenerate a microphone signal carrying the voice signal and the tonesignal; a modulating unit for modulating the microphone signal on thepredetermined wireless microphone frequency channel carrying the voicesignal and the tone signal generated by the mixing unit with a carriersignal to generate the radio microphone signal on the predeterminedwireless microphone frequency channel carrying the voice signal and thetone signal; a transmission unit for transmitting the radio microphonesignal on the predetermined wireless microphone frequency channelcarrying the voice signal indicative of the voice information and thetone signal indicative of the data information modulated by themodulating unit, therethrough, and the wireless receiving apparatusincluding: a receiving unit for receiving the radio microphone signal onthe predetermined wireless microphone frequency channel carrying thevoice signal indicative of the voice information and the tone signalindicative of the data information transmitted by the wirelessmicrophone transmission apparatus; a demodulating unit for demodulatingthe radio microphone signal on the predetermined wireless microphonefrequency channel carrying the voice information and the tone signalreceived by the receiving unit to generate the microphone signal; avoice signal filtering unit for filtering the voice signal indicative ofthe voice information therethrough from the microphone signal generatedby the demodulating unit; a tone signal filtering unit for filtering thetone signal therethrough from the microphone signal generated by thedemodulating unit; an integral computing unit for sequentially computingintegrals of the signal levels of the tones of the tone signal passedthrough by the tone signal filtering unit, at first predetermined timeintervals; a data information computing unit for sequentially computingdifferences between two respective integrals of the signal levels of thetones of the tone signal computed by the integral computing unit, atrespective second predetermined time intervals each starting at aleading point and ending at a trailing point to acquire the datainformation on the basis of the differences; a data informationoutputting unit for outputting the data information acquired by the datainformation computing unit, therethrough; and a voice informationoutputting unit for outputting the voice information on the basis of thevoice signal filtered through by the voice signal filtering unit,therethrough, in accordance with the data information outputted by thedata information outputting unit.

[0029] In accordance with a fourth aspect of the present invention,there is provided a wireless communications system for transmitting andreceiving a radio microphone signal carrying a voice signal indicativeof voice information and a tone signal indicative of data information,comprising: at least one wireless microphone transmission apparatus fortransmitting the radio microphone signal on a predetermined wirelessmicrophone frequency channel carrying the voice signal and the tonesignal; and a plurality of wireless receiving apparatuses for receivingthe radio microphone signal on the predetermined wireless microphonefrequency channel carrying the voice signal and the tone signaltransmitted by the wireless microphone transmission apparatus, thewireless microphone frequency channel allocated to each of the wirelessmicrophone transmission apparatuses and the wireless receivingapparatuses, the wireless microphone transmission apparatus operative totransmit the radio microphone signal on the predetermined wirelessmicrophone frequency channel to one or more specified wireless receivingapparatuses including: a voice inputting unit for inputting the voiceinformation therethrough to generate the voice signal indicative of thevoice information; a data inputting unit for inputting the datainformation therethrough; a tone signal generating unit for generatingthe tone signal indicative of the data information on the basis of thedata information inputted by the data inputting unit, the tone signalhaving a plurality of tones each having a signal level and repeated atpredetermined time intervals; a mixing unit for mixing the voice signalgenerated by the voice inputting unit and the tone signal generated bythe tone signal generating unit to generate a microphone signal carryingthe voice signal and the tone signal; a modulating unit for modulatingthe microphone signal carrying the voice signal and the tone signalgenerated by the mixing unit with a carrier signal to generate the radiomicrophone signal on the predetermined wireless microphone frequencychannel carrying the voice signal and the tone signal; a transmissionunit for transmitting the radio microphone signal on the predeterminedwireless microphone frequency channel carrying the voice signalindicative of the voice information and the tone signal indicative ofthe data information modulated by the modulating unit, therethrough, andthe wireless receiving apparatus including: a receiving unit forreceiving the radio microphone signal on the predetermined wirelessmicrophone frequency channel carrying the voice signal indicative of thevoice information and the tone signal indicative of the data informationtransmitted by the wireless microphone transmission apparatus; ademodulating unit for demodulating the radio microphone signal on thepredetermined wireless microphone frequency channel carrying the voiceinformation and the tone signal received by the receiving unit togenerate the microphone signal; a voice signal filtering unit forfiltering the voice signal indicative of the voice informationtherethrough from the microphone signal generated by the demodulatingunit; a tone signal filtering unit for filtering the tone signaltherethrough from the microphone signal generated by the demodulatingunit; an integral computing unit for sequentially computing integrals ofthe signal levels of the tones of the tone signal passed through by thetone signal filtering unit, at first predetermined time intervals; adata information computing unit for sequentially computing differencesbetween two respective integrals of the signal levels of the tones ofthe tone signal computed by the integral computing unit, at respectivesecond predetermined time intervals each starting at a leading point andending at a trailing point to acquire the data information on the basisof the differences; a data information outputting unit for outputtingthe data information acquired by the data information computing unit,therethrough; and a voice information outputting unit for outputting thevoice information on the basis of the voice signal filtered through bythe voice signal filtering unit, therethrough, in accordance with thedata information outputted by the data information outputting unit.

[0030] In the aforesaid wireless communications system, the datainformation computing unit of the wireless receiving apparatus may beoperative to judge whether the integrals of the signal levels of thetones of the tone signal computed by the integral computing unit are ina predetermined detectable range, and if the data information computingunit judges that the integrals of the signal levels of the tones of thetone signal are not in the predetermined detectable range, the datainformation computing unit is operative to instruct the integralcomputing unit of the wireless receiving apparatus to compensate theintegrals thus computed so that the integrals thus compensated are inthe predetermined detectable range, and the data information computingunit is operative to sequentially compute differences between tworespective integrals of the signal levels of the tones of the tonesignal compensated by the integral computing unit, at respective secondpredetermined time intervals each starting at a leading point and endingat a trailing point to acquire the data information on the basis of thedifferences.

[0031] In the aforesaid wireless communications system, the datainformation may include sound level control data information, the datainputting unit of the wireless microphone transmission apparatus isequipped with a sound level control unit for inputting the sound levelcontrol data information therethrough, the data tone signal generatingunit of the wireless microphone transmission apparatus is operative togenerate a tone signal indicative of the data information including thesound level control data information, the wireless receiving apparatusis operative to receive the radio microphone signal on the predeterminedwireless microphone frequency channel carrying the voice signalindicative of the voice information and the tone signal indicative ofthe data information including the sound level control data informationtransmitted by the wireless microphone transmission apparatus, and thedata information outputting unit of the wireless receiving apparatus isoperative to output the data information including the sound levelcontrol data information.

[0032] In the aforesaid wireless communications system, the datainformation may include a plurality of control data informationelements, the data inputting unit of the wireless microphonetransmission apparatus is equipped with a plurality of operationswitches each for inputting the control data information elementtherethrough in accordance with an operation mode, and a mode selectionswitch for inputting mode information therethrough to select theoperation mode from among a plurality of operation modes on the basis ofthe mode information, the data tone signal generating unit of thewireless microphone transmission apparatus is operative to generate atone signal indicative of the data information including the controldata information elements inputted by the operation switch, the wirelessreceiving apparatus is operative to receive the radio microphone signalon the predetermined wireless microphone frequency channel carrying thevoice signal indicative of the voice information and the tone signalindicative of the data information including the control datainformation element transmitted by the wireless microphone transmissionapparatus, and the data information outputting unit of the wirelessreceiving apparatus is operative to output the data informationincluding the control data information element.

[0033] In the aforesaid wireless communications system, the wirelessreceiving apparatus may be operative to receive the radio microphonesignal on the predetermined wireless microphone frequency channelcarrying the voice signal indicative of the voice information and thetone signal indicative of the data information including the sound levelcontrol data information sequentially transmitted by one or morewireless microphone transmission apparatuses, and the data informationoutputting unit of the wireless receiving apparatus is operative tosequentially output the data information including the sound levelcontrol data information.

[0034] The aforesaid wireless communications system may comprise anaudio system electrically connected with the wireless receivingapparatus, in which the data information includes audio system controldata, the data information outputting unit of the wireless receivingapparatus is operative to output the audio system control data to theaudio system, the voice information outputting unit of the wirelessreceiving apparatus is operative to output the voice information to theaudio system, and the audio system is operative to operate in accordancewith the audio system control data.

[0035] The aforesaid wireless communications system may further comprisean audio-visual system electrically connected with the wirelessreceiving apparatus, in which the data information includes audio-visualsystem control data, the data information outputting unit of thewireless receiving apparatus is operative to output the audio-visualsystem control data to the audio-visual system, the voice informationoutputting unit of the wireless receiving apparatus is operative tooutput the voice information to the audio-visual system, and theaudio-visual system is operative to operate in accordance with theaudio-visual system control data.

[0036] In the aforesaid wireless communications system, the datainformation outputting unit of the wireless receiving apparatus may becapable of being electrically connected with an external device andoutputting the data information to the external device.

[0037] In the aforesaid wireless communications system, the voiceinformation outputting unit of the wireless receiving apparatus may becapable of being electrically connected with an external device andoutputting the voice information to the external device.

[0038] In accordance with a fifth aspect of the present invention, thereis provided a wireless microphone transmission apparatus fortransmitting a radio microphone signal on a predetermined wirelessmicrophone frequency channel carrying a voice signal indicative of voiceinformation and a tone signal indicative of data information,comprising: a voice inputting unit for inputting the voice informationtherethrough to generate the voice signal indicative of the voiceinformation; a data inputting unit for inputting the data informationtherethrough; a tone signal generating unit for generating the tonesignal indicative of the data information on the basis of the datainformation inputted by the data inputting unit, the tone signal havinga plurality of tones each having a signal level and repeated atpredetermined time intervals; a mixing unit for mixing the voice signalgenerated by the voice inputting unit and the tone signal generated bythe tone signal generating unit to generate a microphone signal carryingthe voice signal and the tone signal; a modulating unit for modulatingthe microphone signal carrying the voice signal and the tone signalgenerated by the mixing unit with a carrier signal to generate the radiomicrophone signal on the predetermined wireless microphone frequencychannel carrying the voice signal and the tone signal; and atransmission unit for transmitting the radio microphone signal on thepredetermined wireless microphone frequency channel carrying the voicesignal indicative of the voice information and the tone signalindicative of the data information modulated by the modulating unit,therethrough.

[0039] In the aforesaid wireless microphone transmission apparatus, thewireless microphone transmission apparatus may be operative to transmitthe radio microphone signal on the predetermined wireless microphonefrequency channel to one or more specified wireless receivingapparatuses.

[0040] In the aforesaid wireless microphone transmission apparatus, thedata information may include sound level control data information, thedata inputting unit is equipped with a sound level control unit forinputting the sound level control data information therethrough, thedata tone signal generating unit is operative to generate a tone signalindicative of the data information including the sound level controldata information.

[0041] In the aforesaid wireless microphone transmission apparatus, thedata information may include a plurality of control data informationelements, the data inputting unit is equipped with a plurality ofoperation switches each for inputting the control data informationelement therethrough in accordance with an operation mode, and a modeselection switch for inputting mode information therethrough to selectthe operation mode from among a plurality of operation modes on thebasis of the mode information, the data tone signal generating unit isoperative to generate a tone signal indicative of the data informationincluding the control data information elements inputted by theoperation switch.

[0042] In accordance with a sixth aspect of the present invention, thereis provided a wireless receiving apparatus for receiving a radiomicrophone signal on a predetermined wireless microphone frequencychannel carrying a voice signal indicative of voice information and atone signal indicative of data information, comprising: a receiving unitfor receiving the radio microphone signal on the predetermined wirelessmicrophone frequency channel carrying the voice signal indicative of thevoice information and the tone signal indicative of the datainformation; a demodulating unit for demodulating the radio microphonesignal on the predetermined wireless microphone frequency channelcarrying the voice information and the tone signal received by thereceiving unit to generate the microphone signal; a voice signalfiltering unit for filtering the voice signal indicative of the voiceinformation therethrough from the microphone signal generated by thedemodulating unit; a tone signal filtering unit for filtering the tonesignal therethrough from the microphone signal generated by thedemodulating unit; an integral computing unit for sequentially computingintegrals of the signal levels of the tones of the tone signal passedthrough by the tone signal filtering unit, at first predetermined timeintervals; a data information computing unit for sequentially computingdifferences between two respective integrals of the signal levels of thetones of the tone signal computed by the integral computing unit, atrespective second predetermined time intervals each starting at aleading point and ending at a trailing point to acquire the datainformation on the basis of the differences; a data informationoutputting unit for outputting the data information acquired by the datainformation computing unit, therethrough; and a voice informationoutputting unit for outputting the voice information on the basis of thevoice signal filtered through by the voice signal filtering unit,therethrough, in accordance with the data information outputted by thedata information outputting unit.

[0043] In the aforesaid wireless receiving apparatus, the datainformation computing unit may be operative to judge whether theintegrals of the signal levels of the tones of the tone signal computedby the integral computing unit are in a predetermined detectable range,and if the data information computing unit judges that the integrals ofthe signal levels of the tones of the tone signal are not in thepredetermined detectable range, the data information computing unit isoperative to instruct the integral computing unit to compensate theintegrals thus computed so that the integrals thus compensated are inthe predetermined detectable range, and the data information computingunit is operative to sequentially compute differences between tworespective integrals of the signal levels of the tones of the tonesignal compensated by the integral computing unit, at respective secondpredetermined time intervals each starting at a leading point and endingat a trailing point to acquire the data information on the basis of thedifferences.

[0044] In the aforesaid wireless receiving apparatus, the receiving unitmay be operative to receive the radio microphone signal on thepredetermined wireless microphone frequency channel carrying the voicesignal indicative of the voice information and the tone signalindicative of the data information sequentially transmitted by one ormore wireless microphone transmission apparatuses, and the datainformation outputting unit is operative to sequentially output the datainformation.

[0045] The aforesaid wireless receiving apparatus may further comprise aterminal to be electrically connectable with an audio system, the datainformation including audio system control data, the data informationoutputting unit operative to output the audio system control data to theaudio system, and the voice information outputting unit operative tooutput the voice information to the audio system.

[0046] The aforesaid wireless receiving apparatus may further comprise aterminal to be electrically connectable with an audio-visual system, thedata information including audio-visual system control data, the datainformation outputting unit operative to output the audio-visual systemcontrol data to the audio-visual system, and the voice informationoutputting unit operative to output the voice information to theaudio-visual system.

[0047] In the aforesaid wireless receiving apparatus, the datainformation outputting unit may be capable of being electricallyconnected with an external device and outputting the data information tothe external device.

[0048] In the aforesaid wireless receiving apparatus, the voiceinformation outputting unit may be capable of being electricallyconnected with an external device and outputting the voice informationto the external device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention and many of the attendant advantagesthereof will be better understood from the following detaileddescription when considered in connection with the accompanyingdrawings, wherein:

[0050]FIG. 1 is a schematic block diagram of a wireless communicationssystem according to the present invention;

[0051]FIG. 2 is a schematic block diagram of a wireless microphonetransmission apparatus 101 according to the present invention;

[0052]FIG. 3 is a schematic block diagram of a wireless receivingapparatus 102 according to the present invention;

[0053]FIG. 4 is a schematic block diagram and a graph used fordescribing a principle of transmitting a tone signal;

[0054]FIG. 5 is a schematic block diagram of an example of a bit patternof a tone signal used by a communications system according to thepresent invention;

[0055]FIG. 6 is a graph used for describing a principle of detectingdata information conveyed in the tone signal shown in FIG. 5;

[0056]FIG. 7 is a set of schematic block diagrams and a graph showingfluctuations of voltage characteristics generated in accordance with thesame tone signal shown in FIG. 5;

[0057]FIG. 8 is a set of graphs showing temperature characteristics of acrystal filter;

[0058]FIG. 9 is a graph used for describing the operation ofcompensating signal levels of tones of a tone signal performed by thewireless receiving apparatus 102 according shown in FIG. 3;

[0059]FIG. 10 is a table showing a structure of a 7-bit data string usedfor a communications system according to the present invention;

[0060]FIG. 11 is a table showing a structure of a 13-bit data stringused for a communications system according to the present invention;

[0061]FIG. 12 is a schematic block diagram showing the wirelessmicrophone transmission apparatus 101 shown in FIG. 2 and an enlargedview showing its operation section;

[0062]FIG. 13 is a block diagram showing the operation of an operationsection of the wireless microphone transmission apparatus 101 shown inFIG. 2;

[0063]FIG. 14 is a flowchart showing the operation of the wirelessmicrophone transmission apparatus 101 shown in FIG. 2;

[0064]FIG. 15 is a flowchart showing the operation of the wirelessreceiving apparatus 102 shown in FIG. 3;

[0065]FIG. 16 is a flowchart showing the operation of computing bit dataelements forming data information performed by the wireless receivingapparatus 102 shown in FIG. 3;

[0066]FIG. 17 is a graph used for describing the operation of computingbit data elements forming data information performed by the wirelessreceiving apparatus 102 shown in FIG. 3;

[0067]FIG. 18 is a schematic block diagram used for describing a timersetting performed by the wireless receiving apparatus 102 shown in FIG.3;

[0068]FIG. 19 is a graph used for describing the turn-OFF operation of awireless microphone transmission apparatus performed by the wirelessreceiving apparatus 102 shown in FIG. 3;

[0069]FIG. 20 is a block diagram showing the voice output operation ofwireless receiving apparatuses 102 a and 102 b according to the presentinvention;

[0070]FIG. 21 is a schematic block diagram showing a conventionalwireless microphone transmission apparatus 710;

[0071]FIG. 22 is a schematic block diagram showing a conventionalwireless receiving apparatus 740; and

[0072]FIG. 23 is a graph used for describing a transmission signalincluding a voice signal and a tone signal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0073] Referring now to FIGS. 1 to 20 of the drawing, there is bestshown a preferred embodiment of a communications system, a communicationmethod, a wireless communications system, a wireless microphonetransmission apparatus, and a wireless receiving apparatus according tothe present invention.

[0074] Throughout the following detailed description, similar referencecharacters refer to similar elements in all figures of the drawings.

[0075] As shown in FIG. 1, a wireless communications system 100 fortransmitting and receiving a radio transmission signal, i.e., a radiomicrophone signal on a predetermined wireless microphone frequencychannel carrying a voice signal indicative of voice information and atone signal indicative of data information according to the presentinvention comprises a wireless microphone transmission apparatuses 101 aand 101 b each for transmitting the radio microphone signal on arespective predetermined wireless microphone frequency channel carryingthe voice signal and the tone signal, and a wireless receiving apparatus102 for receiving the radio microphone signal on the predeterminedwireless microphone frequency channel carrying the voice signal and thetone signal transmitted by the wireless microphone transmissionapparatus 101. A predetermined wireless microphone frequency channel isallocated to the wireless microphone transmission apparatus 101 and thewireless receiving apparatus 102.

[0076] The wireless microphone transmission apparatus 101 is shown inFIG. 2 as including a voice inputting section 20, a data inputtingsection 21, a data generating section 22, a tone signal generatingsection 23, a mixing section 24, an oscillation section 25, a modulatingsection 26, a high-frequency amplifying section 27, and a transmissionantenna 28.

[0077] The voice inputting section 20 is adapted to input a voicetherethrough to generate a voice signal indicative of the voiceinformation. The voice inputting section 20 constitutes the voiceinputting unit according to the present invention. The data inputtingsection 21 is adapted to input data information therethrough. The datainputting section 21 constitutes the data inputting unit according tothe present invention. The data generating section 22 is adapted toinput the data information inputted by the data inputting section 21 togenerate a data string indicative of the data information to beoutputted to the tone signal generating section 23. The tone signalgenerating section 23 is adapted to input the data string from the datagenerating section 22 to generate a tone signal indicative of the datainformation on the basis of the data string inputted by the datagenerating section 22. The tone signal has a plurality of tones repeatedat predetermined time intervals. Each tone has a signal level. The datagenerating section 22 and the tone signal generating section 23constitute the tone signal generating unit according to the presentinvention. The mixing section 24 is adapted to input the voice signalgenerated by the voice inputting section 20 and the tone signalgenerated by the tone signal generating section 23 to mix the voicesignal and the tone signal to generate a microphone signal carrying thevoice signal and the tone signal. The mixing section 24 constitutes themixing unit according to the present invention. The oscillation section25 is adapted to generate a carrier signal. The modulating section 26 isadapted to input the microphone signal from the mixing section 24 andthe carrier signal from the oscillation section 25 to modulate themicrophone signal carrying the voice signal and the tone signal with thecarrier signal to generate a radio microphone signal on a predeterminedwireless microphone frequency channel carrying the voice signal and thetone signal. The oscillation section 25 and the modulating section 26constitute the modulating unit according to the present invention. Thehigh-frequency amplifying section 27 is adapted to receive the radiomicrophone signal on the wireless microphone frequency channel from themodulating section 26 to amplify the radio microphone signal. Thetransmission antenna 28 is adapted to receive and transmit the radiomicrophone signal on the wireless microphone frequency channel carryingthe voice signal and the tone signal thus amplified. The high-frequencyamplifying section 27 and the transmission antenna 28 constitute thetransmission unit according to the present invention. The wirelessmicrophone transmission apparatuses 101, 101 a and 101 b constitute thetransmission means and the wireless transmission apparatus according tothe present invention.

[0078] The wireless receiving apparatus 102 is shown in FIG. 3 ascomprising a receiving antenna 42, a high-frequency amplifying section30, a frequency conversion section 31, an intermediate-frequencyamplifying section 32, a decoding section 33, a BPF, i.e., a band passfilter 34, a squelch circuit section 35, a low-frequency amplifyingsection 36, a crystal filter 37, a squelch circuit control section 38, adata information computing section 39, a control section 40, a controlsignal outputting section 41, a display section 43. The receivingantenna 42 is adapted to receive the radio microphone signal on thepredetermined wireless microphone frequency channel carrying the voicesignal indicative of the voice information and the tone signalindicative of the data information transmitted by the wirelessmicrophone transmission apparatus 101. The high-frequency amplifyingsection 30 is adapted to receive the radio microphone signal from thereceiving antenna 42 and amplify the radio microphone signal thusreceived. The receiving antenna 42 and the high-frequency amplifyingsection 30 constitute the receiving unit according to the presentinvention. The frequency conversion section 31 includes a selectingsection 31 a and a frequency mixing section 31 b. The selecting section31 a is adapted to select and generate a wireless microphone channelfrequency and the frequency mixing section 31 b is adapted to mix theradio microphone signal amplified by the high-frequency amplifyingsection 30 and the wireless microphone channel frequency generated bythe frequency mixing section 31 b to generate a intermediate-frequencymicrophone signal. The intermediate-frequency amplifying section 32 isadapted to amplify the intermediate-frequency microphone signal thusgenerated. The decoding section 33 is adapted to decode theintermediate-frequency microphone signal thus amplified to generate amicrophone signal to be outputted to the band pass filter 34 and thecrystal filter 37. The frequency conversion section 31, theintermediate-frequency amplifying section 32, and the decoding section33 constitute the demodulating unit according to the present invention.The band pass filter 34 is adapted to filter a voice signal therethroughfrom the microphone signal generated by the decoding section 33 tooutput the filtered voice signal to the squelch circuit section 35. Theband pass filter 34 constitutes the voice signal filtering unitaccording to the present invention. The squelch circuit section 35 isadapted to cut off or pass therethrough the voice signal filteredthrough by the band pass filter 34 to the low-frequency amplifyingsection 36. The low-frequency amplifying section 36 is adapted toamplify the voice signal passed through by the squelch circuit section35 to output the amplified voice signal to constituent component(s), notshown. Furthermore, the low-frequency amplifying section 36 may becapable of being electrically connected with an external device, notshown by means of, for example, a terminal, and outputting the voiceinformation to the external device. The squelch circuit section 35 andthe low-frequency amplifying section 36 constitute the voice informationoutputting unit according to the present invention.

[0079] The crystal filter 37 is adapted to filter a tone signaltherethrough from the microphone signal generated by the decodingsection 33 to output the tone signal thus filtered to the squelchcircuit control section 38 and the data information computing section39. The crystal filter 37 constitutes the tone signal filtering unitaccording to the present invention. The squelch circuit control section38 is adapted to control the squelch circuit section 35 to pass throughor cut off the voice signal in accordance with the tone signal filteredthrough by the crystal filter 37. The wireless receiving apparatus 102constitutes the receiving means and the wireless receiving apparatusaccording to the present invention.

[0080] The operation of the squelch circuit section 35 and the squelchcircuit control section 38 will be hereinlater described in detail.

[0081] The squelch circuit control section 38 is operated toelectrically connect the squelch circuit section 35 with thelow-frequency amplifying section 36 to pass through the voice signalfrom the squelch circuit section 35 to the low-frequency amplifyingsection 36 if the tone signal is inputted to the squelch circuit controlsection 38 from the crystal filter 37. On the other hand, the squelchcircuit control section 38 is operated to electrically disconnect thesquelch circuit section 35 from the low-frequency amplifying section 36to cut off the voice signal to be passed through from the squelchcircuit section 35 to the low-frequency amplifying section 36 if no tonesignal is inputted to the squelch circuit control section 38 from thecrystal filter 37. The operation of electrically connecting the squelchcircuit section 35 with the low-frequency amplifying section 36 to passthrough the voice signal from the squelch circuit section 35 to thelow-frequency amplifying section 36 will be hereinlater referred to as“squelch-off” and the operation of electrically disconnecting thesquelch circuit section 35 from the low-frequency amplifying section 36to cut off the voice signal to be passed through from the squelchcircuit section 35 to the low-frequency amplifying section 36 will behereinlater referred to as “squelch-on”.

[0082] The data information computing section 39 is operated to computedata information in accordance with the tone signal filtered through bythe crystal filter 37 and output the data information to the controlsection 40. The operation of the data information computing section 39to compute the data information in accordance with the tone signalcarried in the radio microphone signal transmitted by the wirelessmicrophone transmission apparatus 101 will be described later.

[0083] The control section 40 is operated to input the data informationoutputted by the data information computing section 39 and output thedata information to the control signal outputting section 41 and thedisplay section 43. The display section is operated to display the datainformation. The control signal outputting section 41 is operated toreceive the data information from the control section 40 to generate andoutput control signal(s) to be outputted to related constituentcomponent(s), not shown. The constituent components may be controlconstituent components of the wireless receiving apparatus 102. Thismeans that the control section 40 can control constituent components inaccordance with the data information received from the data informationcomputing section 39. Furthermore, the control signal outputting section41 may be capable of being electrically connected by means of, forinstance, a terminal with an external device including an audio-visualsystem and outputting the data information to the external device.

[0084] Alternatively, the control section 40 can control, for instance,the sound level of the voice signal outputted by the low-frequencyamplifying section 36 in accordance with the data information.Similarly, the control section can control the sound level of the voicesignal carried in the radio microphone signal transmitted by the otherwireless microphone transmission apparatus, outputted by thelow-frequency amplifying section 36 by changing switching the microphonefrequency channel in accordance with the data information.

[0085] More particularly, the wireless receiving apparatus 102 accordingto the present invention can selectively receive any one of radiomicrophone signals on microphone frequency channels A and B, transmittedby the respective wireless microphone transmission apparatuses 101 a and101 b. The microphone frequency channels A and B are allocated to thewireless microphone transmission apparatuses 101 a and 101 b,respectively. The control section 40 can, therefore, control the soundlevel of the voice signal carried in the radio microphone signaltransmitted by any one of the wireless microphone transmissionapparatuses 101 a and 101 b, outputted by the low-frequency amplifyingsection 36, by switching the microphone frequency channel to either oneof the microphone frequency channels A and B, in accordance with thedata information outputted by the data information computing section 39.

[0086] In the wireless microphone communications system 100 according tothe present invention, the circuit to the control signal outputtingsection 41 is operated to be closed only when the data information isinputted, thereby enabling to save power. This means that no voltage isapplied to the control signal outputting section 41 when no datainformation is inputted. The squelch circuit control section 38, thecontrol section 40, signal outputting section 41 and the display section43 constitute the data information outputting unit according to thepresent invention.

[0087] As described above, the wireless receiving apparatus 102according to the present invention can selectively receive a radiomicrophone signal on a frequency channel from any one of two wirelessmicrophone transmission apparatuses 101 a and 101 b. The wirelessmicrophone transmission apparatuses 101 a and 101 b have predeterminedmicrophone frequency channels A and B, respectively. This means that thewireless receiving apparatus 102 comprises two sets of thehigh-frequency amplifying section 30, the frequency conversion section31, the intermediate-frequency amplifying section 32, the decodingsection 33, the band pass filter 34, the squelch circuit section 35, thelow-frequency amplifying section 36, the crystal filter 37, the squelchcircuit control section 38, the data information computing section 39,the control section 40, and the control signal outputting section 41,each of which is dedicated to the microphone respective frequencychannels A and B allocated to the respective wireless microphonetransmission apparatuses 101 a and 101 b.

[0088] The tone signal indicative of the data information will behereinlater described in detail.

[0089] The tone signal generating section 23 is operated to generate thetone signal when the wireless microphone transmission apparatus 101 ispowered on. The tone signal thus generated is carried in the radiomicrophone signal and transmitted from the wireless microphonetransmission apparatus 101 to the wireless receiving apparatus 102. Inthe wireless receiving apparatus 102, the crystal filter 37 is operatedto filter the tone signal therethrough from the microphone signaldecoded by the decoding section 33. The squelch circuit control section38 is operated to receive the tone signal filtered through by thecrystal filter 37, and control the squelch circuit section 35 to havethe voice signal passed therethrough.

[0090] No tone signal is generated by the tone signal generating section23 nor transmitted from the wireless microphone transmission apparatus101 to the wireless receiving apparatus 102 when, on the other hand, thewireless microphone transmission apparatus 101 is powered off. In thewireless receiving apparatus 102, the squelch circuit control section 38is operated to electrically disconnect the squelch circuit section 35from the low-frequency amplifying section 36 to cut off the voice signalsince no tone signal is inputted from the crystal filter 37.

[0091] The wireless receiving apparatus 102 is accordingly operated tooutput no voice signal when no radio microphone signal carrying tonesignal is received, thereby enabling to prevent high level of noisesignals from being outputted.

[0092] The wireless communications system 100 according to the presentinvention, furthermore, is operated to transmit and receive a tonesignal indicative of data information carried in a radio microphonesignal between the wireless microphone transmission apparatus 101 andthe wireless receiving apparatus 102.

[0093] As shown in FIG. 4, a tone signal indicative of data informationhas a plurality of tones. The tones forming one tone signal have asignal level, and are repeated at predetermined time intervals. The timeinterval at which tones are repeated changes for every 40 milliseconds.

[0094] The time period of 40 milliseconds is a time period required totransmit one-bit data element. The squelch circuit control section 38does not squelch-on the squelch circuit section 35 until 40 millisecondselapse since no tone signal is received. In the wireless communicationssystem 100 according to the present invention, the time period of 40milliseconds therefore represents one-bit data element.

[0095] The time period representing one-bit data element being shorterthan 40 milliseconds may lead the wireless receiving apparatus 102 tomisidentify the tone signal, thereby causing the squelch circuit controlsection 38 to erroneously squelch-off the squelch circuit section 35 tooutput a noise signal.

[0096] The time period of 40 milliseconds is appropriate for thewireless receiving apparatus 102 to identify the absence or presence ofthe tone signal, thereby causing the squelch circuit control section 38to accurately squelch-on and squelch-off the squelch circuit section 35,thereby enabling to prevent the wanted voice signal from being cut offand a noise signal from being outputted.

[0097]FIG. 5 shows an example of tones forming bit data elements of atone signal carried in the microphone signal. A pattern of tones formingbit data elements is hereinlater referred to as a “bit pattern”.

[0098] The bit pattern shown in FIG. 5 comprises one start bit, i.e.,one start bit element, two pieces of low data, i.e., two low dataelements and two pieces of high data, i.e., two high data elements. Thestart bit element is a bit data element having no tone for the timeperiod of one bit-data element. The low data element is a bit dataelement having a plurality of tones repeated at a predetermined timeinterval. The high data element is a bit data element having one tonefor the time period of one bit-data element.

[0099] In the wireless communications system 100 according to thepresent invention, the wireless microphone transmission apparatus 101comprises a data generating section 22 for generating a tone signalindicative of data information including the aforesaid start bitelement, low data elements and high data elements on the basis of thedata information inputted by the data inputting section 21.

[0100] The operation of the data information computing section 39 tocompute the data information in accordance with the tone signal carriedin the radio microphone signal transmitted by the wireless microphonetransmission apparatus 101 will be hereinlater described in detail.

[0101] The data information computing section 39 is operated to rectifya tone signal filtered through by crystal filter 37 and compute theintegrals of the signal levels of the tones of the tone signal levelthus rectified at predetermined integration time intervals. Moreparticularly, the data information computing section 39 includes anintegral computing section 39 a and a data determining section 39 b. Theintegral computing section 39 a is operated to rectify the tone signalfiltered through by the crystal filter 37 and sequentially compute theintegrals of the signal levels of the tones of the tone signal thusrectified at predetermined integration time intervals.

[0102]FIG. 6 shows an example of the voltage characteristicscorresponding to the integrals of the signal levels of the tones of thetone signal computed by the integral computing section 39 a. The startbit element is a data element having no tone for the time period of onebit data element, thereby forming a rapid discharging slope of voltagelevel. The low data element is a data element having a plurality oftones repeated at a predetermined time interval, thereby forming agentle discharging slope of voltage level. The high data element is adata element having one tone for the time period of one bit-dataelement, thereby forming a charging slope of voltage level. Furthermore,the signal level of a tone of a tone signal has an upper limit and alower limit as shown in FIG. 6. The high data elements continueuninterruptedly, thereby resulting in that the signal level of the toneof the tone signal approaches to the upper limit. The low data elements,on the other hand, continue uninterruptedly, thereby resulting in thatthe signal level of the tone of the tone signal approaches to the lowerlimit.

[0103] As will be seen from FIG. 6, a bit data element conveyed in thetone signal can be determined by computing a slope formed by the signallevels of the integrals of the signal levels of the tones of the tonesignal passed through by the crystal filter 37. The slope can becomputed by a difference between two respective integrals of the signallevels of the tones of the tons signal computed by the data informationcomputing section 39, at a predetermined detecting time intervalstarting at a leading point and ending at a trailing point. In otherwords, the bit data element, i.e., start bit element, low data elementor high data element, can be detected in accordance with the slope.

[0104] The data determining section 39 b is operated to sequentiallycompute differences between two respective integrals of the signallevels of the tones of the tone signal computed by the integralcomputing section 39 a, at respective predetermined detecting timeintervals each starting at a leading point and ending at a trailingpoint to acquire the bit data elements forming the data informationindicative of the data information on the basis of the differences asshown in FIG. 6.

[0105] Two low data elements, however, continue uninterruptedly, therebymaking it possible for a difference between two integrals of the signallevels of the tones of the tone signal computed at the detecting timeinterval starting at a leading point and ending at a trailing point toresult in zero. Similarly, two high data elements continueuninterruptedly, thereby making it possible for a difference between twointegrals of the signal levels of the tones of the tone signal computedat the detecting time interval starting at a leading point and ending ata trailing point to result in zero. When the difference thus computedresults in zero, the data determining section 39 b is therefore operatedto determine the bit data element forming the tone signal indicative ofthe data information to be high data element or low data element, byjudging if the signal level of the tone of the tone signal is detectedin the vicinity of the upper limit or in the vicinity of the lowerlimit.

[0106] The compensating operation of the signal levels of the tones ofthe tone signal filtered through by the crystal filter 37 will behereinlater described in detail.

[0107] The integral computing section 39 a is operated to rectify thetone signal passed through by the crystal filter 37 and sequentiallycompute the integrals of the signal levels of the tones of the tonesignal thus rectified at predetermined integration time intervals. Thesignal levels of the tones of the tone signal passed through by thecrystal filter 37 may, however, fluctuate due to various factorsincluding the temperature characteristics of the crystal filter 37 andthe receiving state of the wireless receiving apparatus 102. Thefluctuation of the signal levels of the tones of the tone signal maylead the integral computing section 39 a to misidentify the tones of thetone signal and the data determining section 39 b to fail to determineexact bit data elements forming the data information.

[0108]FIG. 7 shows the signal levels of the tones of the tone signals(a), (b), and (c) passed through by the crystal filter 37 and theirrespective integral curves. As will be seen from FIG. 7, tone signals(a), (b), and (c) are intended to convey the same bit data elementforming the same data information, but have different signal levels,thereby resulting in forming different integral curves, respectively.The fluctuation of the signal levels of the tones of the tone signal maythus deteriorate the sensitivity of the wireless receiving apparatus 102of recognizing the data information conveyed in the tone signal. Thefluctuation of the signal levels of the tones of the tone signal,especially, makes it difficult for the data information computingsection 39 to distinguish the start bit element from the low bitelement. Furthermore, the data determining section 39 b can recognizethe integral of the signal level of the tone of the tone signal only ifit is within a detectable range, which will be described later (see FIG.9).

[0109] The temperature characteristics of the crystal filter 37 causesto fluctuate the signal levels of the tones of the tone signal to befiltered therethrough. FIG. 8 shows the temperature characteristics ofthe crystal filter 37 with respect to the frequency. The crystal filter37 is designed to filter through the tone signal at 32.768 kHz. As shownin FIG. 8(a), the crystal filter 37 has the best sensitivity frequencyof 32.768 kHz at 25° C. The best sensitivity frequency of the crystalfilter 37, however, shifts below the signal frequency of 32.768 kHz at0° C. The shift of the best sensitivity frequency of the crystal filter37 causes the fluctuation of the signal levels of the tones of the tonesignal to be filtered therethrough. In the similar manner to the crystalfilter 37, the modulating section 26 of the wireless microphonetransmission apparatus 101 may cause the fluctuation of the signallevels of the tones of the tone signal to be carried. The fluctuation ofthe signal levels of the tones of the tone signal thus caused will makeit difficult for the wireless receiving apparatus 102 to accuratelydetermine the bit data element forming the data information.

[0110] In order to solve the above drawback, the data determiningsection 39 b is provided with a plurality of reference tables used fordetermining the integrals of the signal levels of the tones of the tonesignal outputted by the integral computing section 39 a. The datadetermining section 39 b is operated to select one reference table fromamong the reference tables on the basis of the integrals of the signallevels of the tones of the tone signal outputted by the integralcomputing section 39 a to compensate the integrals of the signal levelsof the tones of the tone signal in accordance with the reference tableat predetermined compensating time intervals, thereby making it possiblefor the data determining section 39 b to correctly identify theintegrals of the signal levels of the tones of the tone signal even ifthe signal levels of the tones of the tone signal may fluctuate as shownin FIG. 8(b). The data determining section 39 b thus constructed cansequentially compute differences between two respective compensatedintegrals of the signal levels of the tones of the tone signal atrespective data determining time intervals to acquire bit data elementsforming the data information on the basis of the differences.

[0111] The data determining section 39 b is operated to select onereference table from among the plurality of reference tables at thepredetermined compensating time intervals. Once a start bit element isdetected, the data determining section 39 b can not select any otherreference table until the all of the bit data elements of the datastring following the start bit are received.

[0112] This means the data determining section 39 b, however, cannotselect any reference table no matter if the integral of the signal levelof the tone of the tone signal outputted by the integral computingsection 39 a goes out of the detectable range shown in FIG. 9. In orderto solve the drawback, the data determining section 39 b of the presentembodiment of the wireless receiving apparatus 102 according to thepresent invention, can instruct the integral computing section 39 a toincrement or change the voltage level applied to rectify the tone signalfiltered through by the crystal filter 37 to compensate the signal levelof the tone of the tone signal to be outputted to the data determiningsection 39 b as shown in FIG. 9 to ensure that the data determiningsection 39 b selects one reference table from among a plurality ofreference tables on the basis of the compensated signal levels of thetones of the tone signal. The voltage level applied by the integralcomputing section 39 a to rectify the tone signal filtered through bythe crystal filter 37 will be hereinlater referred to as “detectionlever”.

[0113] This means that the data determining section 39 b is operative tojudge whether the integrals of the signal levels of the tones of thetone signal computed by the integral computing unit are in the detectionlevel, and if the data information determining section 39 b judges thatthe integrals of the signal levels of the tones of the tone signalcomputed by the integral computing unit are not in a predetermineddetectable range, the data determining section 39 b is operative toinstruct the integral computing section 39 a to compensate the integralsthus computed so that the integrals thus compensated are in thepredetermined detectable range by incrementing the detection level, andthe data determining section 39 b is operative to sequentially computedifferences between two respective integrals of the signal levels of thetones of the tone signal thus compensated by the integral computingsection 39 a, at respective second predetermined time intervals eachstarting at a leading point and ending at a trailing point to acquirethe data information on the basis of the differences. The integralcomputing section 39 a and the data determining section 39 b constitutethe integral computing unit and the data information computing unitaccording to the present invention.

[0114] The structure of a data string will be described hereinlater.

[0115] Data information can be converted into a data string having a bitlength formed by a plurality of bit data elements. The bit data stringincludes two types consisting of a bit data string of 7-bit length and abit data string of 13-bit length. A bit data string of 7-bit length anda bit data string of 13-bit length are hereinlater referred to as a“7-bit data string” and a “13-bit data string”, respectively.

[0116]FIGS. 10 and 11 show a 7-bit data string and a 13-bit data string,respectively. As shown in FIG. 10 and 11, both of the 7-bit data stringand 13-bit data string include a “start bit element”, a “bit lengthidentifier”, “control data elements”, and “BCC data elements”,respectively.

[0117] The BCC data elements are data elements used for error detectingand allocated to the lower two bits of the 7-bit data string and thelower four bits of the 13-bit data string.

[0118] As described hereinbefore, the time period of 40 milliseconds isrequired to transmit one bit data element. Accordingly, the time periodof 280 milliseconds is required to transmit the 7-bit data string andthe time period of 520 milliseconds is required to transmit the 13-bitdata string. Data information includes an urgent type of datainformation, which expects a quick response from the related constituentcomponent, and a large type of data information, which containsrelatively large volume of information. 7-bit data string is generallyused to convey the urgent type of data information, and 13-bit datastring is generally used to convey the large type of data information.

[0119] This means that the data generating section 22 is operated toinput data information from the data inputting section 21, judge whetherthe type of the data information is the urgent type or the large type.Then, the data generating section 22 is operated to generate a 7-bitdata string in response to the urgent type of data information to beurgently transmitted, and a 13-bit data string, on the other hand, inresponse to the large type of data information having large volume ofinformation. Furthermore, the data information computing section 39 canjudge whether the tone signal is 7-bit data string or 13-bit data stringby checking the second bit of the data string.

[0120] The 7-bit data string includes sound level operation mode dataused for controlling the signal level of the voice signal to beoutputted by the wireless receiving apparatus 102 and control operationmode data used for controlling the control signal to be outputted by thewireless receiving apparatus 102. On the other hand, the 13-bit datastring includes the above stated control operation mode data used forcontrolling the control signal to be outputted by the wireless receivingapparatus 102, and wireless microphone mode data used for transmittingthe operating state of the wireless microphone transmission apparatus101. As described above, both the 7-bit data string and the 13 bit-datastring can convey control operation mode data used for controlling thecontrol signal to be outputted by the wireless receiving apparatus 102.7-bit data string and 13-bit data string are selectively generated toconvey the control operation mode data, depending on the urgency of thecontrol operation. The third bit of the 13-bit data string indicates thedata mode, i.e., whether the data string conveys the control operationmode data or the wireless microphone mode data.

[0121] The wireless receiving apparatus 102 may further compriseterminals to be electrically connectable to an audio system including,for instance, a cassette deck and a CD player, and to audio-visualsystem including, for instance, a video deck. The wireless receivingapparatus 102 may output voice information and data information to theaudio system and audio-visual system from the low-frequency amplifyingsection 36 and the control signal outputting section 41 through theterminals. The control operation mode data may include a plurality ofcontrol data used for controlling, for instance, an audio system such asa cassette deck and a CD player, and an audio-visual system such as avideo deck. This means that the control operation mode data can be used,for instance, to control the power supply of the audio system and theaudio-visual system, to control the sound level of a mixer, therebyadjusting a plurality of sound levels of voice and sound outputted fromthe audio system, to actuate a plurality of light switches, to lift orlower a screen, to control a slide in the audio-visual system, and toactuate an automatic broadcasting device, a sound device, and a displaydevice constituting any one of the audio system and the audio-visualsystem.

[0122] The control operation mode data to be used for controlling thepower supply of the wireless microphone transmission apparatus 101,hereinlater referred to as “power supply control data”, is generated bythe data generating section 22 in the following manner. The supplyvoltage of the wireless microphone transmission apparatus 101 ismeasured by a control section of the wireless microphone transmissionapparatus 101, not shown, at predetermined intervals. The supply voltageof the wireless microphone transmission apparatus 101 thus measured isoutputted to the data inputting section 21. The data generating section22 is operated to generate a data string including the power supplycontrol data on the basis of the data information including the supplyvoltage. The wireless receiving apparatus 102 has a display section, notshown, to display the supply voltage information.

[0123] As will be seen from the foregoing description, the datagenerating section 22 thus constructed is operated to input datainformation from the data inputting section 21, identify the type of thedata information, and, in response to the type, generate a 7-bit datastring or 1 13-bit data string on the basis of the data information.More specifically, the data generating section 22 is operated togenerate a 7-bit data string in response to the urgent type of datainformation, and generate a 13-bit data string in response to the largetype of data information.

[0124] The operation of the wireless microphone transmission apparatus101 will be hereinlater described in detail.

[0125] The wireless microphone transmission apparatus 101 is operated toinput data information in the following manner.

[0126] The data inputting section 21 is equipped with an operatingsection 50 for inputting data information therethrough. Once the datainputting section 21 inputs data information from the operation section50, the data inputting section 21 is operated not to input any otherdata information until the wireless microphone transmission apparatus101 transmits the radio microphone signal carrying the inputted datainformation to ensure that the inputted data information is transmitted.

[0127]FIG. 12 shows an example of the operating section 50. FIG. 13shows the operation of the operating section 50 shown in FIG. 12. Theoperating section 50 constitutes the sound level control unit accordingto the present invention.

[0128] As shown in FIG. 12, the operating section 50 has a modeselection switch 51, a plurality of operation switches 52 a, 52 b, 52 c,and 52 d, a sound level display section 53, and a control informationdisplay section 54. More specifically, the data information includes aplurality of control data elements. The mode selection switch 51 isadapted to input a control data element therethrough to select anoperation mode from among a sound operation mode and a control operationmode. The operation switches 52 a, 52 b, 52 c, and 52 d are adapted toinput a control data element therethrough in accordance with theoperation mode. This means that the operation switches 52 a, 52 b, 52 c,and 52 d are, on the sound operation mode, adapted to input a controldata element therethrough to control the sound level of the voiceinformation to be outputted by the wireless receiving apparatus 102. Thecontrol data element used to control the sound level of the voiceinformation will be hereinlater referred to as “sound level controldata”. The sound level display section 53 is adapted to light-on on thesound operation mode. The mode selection switch 51 constitutes the modeselection switch according to the present invention. The operationswitches 52 a, 52 b, 52 c, and 52 d constitute the operation switchesaccording to the present invention.

[0129] More particularly, the wireless communications system comprisestwo wireless microphone transmission apparatuses 101 a and 101 b, andtwo wireless receiving apparatuses 102 a and 102 b. The wirelessreceiving apparatuses 102 a and 102 b constitute the receiving means andthe wireless receiving apparatus according to the present invention. Thewireless microphone transmission apparatuses 101 a and 101 b are adaptedto transmit radio microphone signals on respective microphone frequencychannels carrying a voice signal indicative of voice information and atone signal indicative of data information to the wireless receivingapparatuses 102 a and 102 b, respectively. The operation switches 52 aand 52 b of the wireless microphone transmission apparatuses 101 a are,on the sound operation mode, adapted to input sound level control datatherethrough to control the sound level of the voice information of thewireless receiving apparatus 102 a, and the operation switches 52 a and52 b of the wireless microphone transmission apparatuses 101 b areadapted, on the sound operation mode, to input sound level control datatherethrough to control the sound level of the voice information of thewireless receiving apparatus 102 b. On the other hand, the operationswitches 52 c and 52 d of the wireless microphone transmissionapparatuses 101 a are, on the sound operation mode, adapted to inputsound level control data therethrough to control the sound level of thevoice information of the wireless receiving apparatus 102 b, and theoperation switches 52 c and 52 d of the wireless microphone transmissionapparatuses 101 b are adapted, on the sound operation mode, to inputsound level control data therethrough to control the sound level of thevoice information of the wireless receiving apparatus 102 a.

[0130] Furthermore, the operation switches 52 a, 52 b, 52 c, and 52 dare, on the control operation mode, adapted to input control datatherethrough to control the operation (other then the sound level) ofthe wireless receiving apparatus 102. The control information displaysection 54 is adapted to light-on on the control operation mode. Thedata used to control the operation will be hereinlater referred to as“operation control data”.

[0131] Referring to FIG. 13, the operation of the operating section 50will be hereinlater described. The mode selection switch 51 andoperation switches 52 a, 52 b, 52 c, and 52 d are usually in the standbystate for waiting for data to be inputted therethrough. The modeselection switch 51 is firstly pressed, thereby resulting in that thesound level display section 53 is lighted-on, the operation section 50is switched to the sound operation mode, and the operation switches 52a, 52 b, 52 c, and 52 d become ready for inputting sound control datatherethrough. The mode selection switch 51 is secondly pressed on thesound operation mode, thereby resulting in that the control informationdisplay section 53 is lighted-on, the operation section 50 is switchedto the control operation mode, and the operation switches 52 a, 52 b, 52c, and 52 d become ready for inputting control operation datatherethrough. In this manner, the operation mode of the operationsection 50 is switched from one operation mode to the other operationmode whenever the mode selection switch 51 is pressed.

[0132] The operation section 50 is, on the other hand, operated toreturn to the standby state, if no data is inputted by the modeselection switch 51, nor by any one of the operation switches 52 a, 52b, 52 c, and 52 d for a predetermined waiting time period.

[0133] The operation of the operation section 50 will be described inmore detail. The operation section 50 is provided with a timer forcounting a time elapsed in which no data is inputted. The timer isinitialized to zero whenever data is inputted by the mode selectionswitch 51, or any one of the operation switches 52 a, 52 b, 52 c, and 52d therethrough. The timer is set for the predetermined waiting timeperiod. This leads to the fact that he operation section 50 is operatedto return to the standby state if the timer expires without data beinginputted for more than the waiting time period.

[0134] The data generating section 22 is operated to input the controldata thus inputted by the operation switches 52 a, 52 b, 52 c, and 52 dto generate a data string to be outputted to the tone signal generatingsection 23.

[0135] Once the data inputting section 21 inputs data information fromthe operation section 50, the data inputting section 21 thus constructeddoes not input any other data information until the wireless microphonetransmission apparatus 101 transmits the radio microphone signalcarrying the inputted data information to ensure that data informationis transmitted.

[0136] Furthermore, the data inputting section 21 is adapted to inputcontrol data information from a control section, not shown. As describedhereinlater, the control data includes supply voltage information of thewireless microphone transmission apparatus 101. In the case that thedata inputting section 21 inputs data information from the operationsection 50 while the control data information inputted from the controlsection is still being processed in the wireless microphone transmissionapparatus 101, the process of the control data is suspended until thewireless microphone transmission apparatus 101 transmits the radiomicrophone signal carrying the data information inputted from theoperation section 50 to ensure that the inputted data information istransmitted.

[0137] The operation of transmitting a radio microphone signal on apredetermined wireless microphone frequency channel carrying a voicesignal indicative of voice information and a tone signal indicative ofdata information will be hereinlater described in detail.

[0138]FIG. 14 shows a flowchart showing the operation of transmitting aradio microphone signal on a predetermined wireless microphone frequencychannel carrying a voice signal indicative of voice information and atone signal indicative of data information performed by the wirelessmicrophone transmission apparatus 101.

[0139] The power switch of the wireless microphone transmissionapparatus 101, not shown, is turned on and the data inputting section 21is ready to receive data information.

[0140] In the step S1, the data inputting section 21 is operated toinput data information from the operation section 50 or the controlsection, not shown, to be outputted to the data generating section 22.If the data information is inputted from the operation section 50 whiledata information inputted from the control section is being processed,the data information inputted from the operation section 50 is givenpriority to the data information inputted from the control section. Thestep S1 goes forward to the step S2 wherein the data generating section22 is operated to identify the type of the data information toselectively generate a 7-bit data string and a 13-bit data string inresponse to the type of and on the basis of the data information thusinputted, and output the data string thus generated to the tone signalgenerating section 23.

[0141] The step S2 goes forward to the step S3 wherein the tone signalgenerating section 23 is operated to generate the tone signal indicativeof the data information on the basis of the data string inputted by thedata generating section 22 and output the tone signal thus generated tothe mixing section 24.

[0142] The step S3 goes forward to the step S4 wherein the mixingsection 24 is operated to input the voice signal from the voiceinputting section 20 and the tone signal from the tone signal generatingsection 23 to mix the voice signal and the tone signal to generate amicrophone signal carrying the voice signal and the tone signal, andoutput the microphone signal thus generated to the modulating section26. The step S4 goes forward to the step S5 wherein the modulatingsection 26 is operated to input the microphone signal from the mixingsection 24 and the carrier signal from the oscillation section 25 tomodulate the microphone signal with the carrier signal to generate aradio microphone on a predetermined wireless microphone frequencychannel carrying the voice signal and the tone signal. The wirelessmicrophone frequency channel is uniquely allocated to the wirelessmicrophone transmission apparatus 101. Then, the high-frequencyamplifying section 27 is operated to receive the radio microphone signalon the wireless microphone frequency from the modulating section 26 toamplify the radio microphone signal, and output the radio microphonesignal thus amplified to the transmission antenna 28. The transmissionantenna 28 is operated to transmit the radio microphone signal on thewireless microphone frequency channel carrying the voice signal and thetone signal to the wireless receiving apparatus 102.

[0143] The step S5 goes forward to the step S6 wherein a timer is set toignore any data input for a predetermined time period.

[0144] As will be seen from the foregoing description, the wirelessmicrophone transmission apparatus 101 thus constructed is operative totransmit the radio microphone signal on the wireless microphonefrequency carrying the voice signal and the tone signal to the wirelessreceiving apparatus 102. The radio microphone signal is allocated to thewireless microphone transmission apparatus 101 and the wirelessreceiving apparatus 102.

[0145] The operation of receiving a radio microphone signal on apredetermined microphone frequency channel carrying a voice signalindicative of voice information and a tone signal indicative of datainformation will be hereinlater described in detail.

[0146]FIG. 15 shows a flowchart showing the operation of receiving aradio microphone signal on a predetermined wireless microphone frequencychannel carrying a voice signal indicative of voice information and atone signal indicative of data information performed by the wirelessreceiving apparatus 102.

[0147] The power switch of the wireless receiving apparatus 102, notshown, is turned on and the wireless receiving apparatus 102 is inprogress of receiving a radio microphone signal on a predeterminedwireless microphone frequency channel carrying a voice signal indicativeof voice information and a tone signal indicative of data informationperformed by the wireless receiving apparatus 102.

[0148] In the step S10, the decoding section 33 is operated to decodethe received radio microphones signal to generate a microphone signal tobe outputted to the band pass filter 34 and the crystal filter 37. Thestep S10 then goes forward to the step S11 and step S12.

[0149] In the step S11, the band pass filter 34 is operated to filterthrough a voice signal from the microphone signal, and output the voicesignal thus filtered through to the squelch circuit section 35. In thestep S12, the crystal filter 37 is operated to filter through a tonesignal from the microphone signal, and output the tone signal thusfiltered through to the squelch circuit control section 38 and the datainformation computing section 39. The step S11 goes forward to the stepS13, and the step S12 goes forward to the step S16.

[0150] The operation of outputting voice information and datainformation is controlled in the following manner.

[0151] In the step S13, the squelch circuit control section 38 isoperated to squelch-off the squelch circuit section 35 to pass throughthe voice signal in response to the signal level of the tone of the tonesignal inputted thereto. The squelch circuit control section 38 is, onthe other hand, operated to squelch-on the squelch circuit section 35 ifno tone signal is inputted thereto or the signal level of the tones ofthe tone signal inputted thereto is smaller than a predeterminedthreshold value.

[0152] The step S13 goes forward to the step S14 wherein the squelchcircuit section 35 is operated to output the voice signal to thelow-frequency amplifying section 36. The step S14 goes forward to thestep S15 wherein the low-frequency amplifying section 36 is operated toamplify the voice signal and output the voice signal thus amplifiedthereto.

[0153] In the step S16, the data information computing section 39 isoperated to compute bit data elements forming the data information inaccordance with the tone signal filtered through by the crystal filter37. The operation of computing bit data elements forming datainformation will be described in detail later.

[0154] The step S16 goes forward to the step S17 wherein the informationcomputing section 39 is operated to determine and construct the dataelements, i.e., the control signal indicative of the data information onthe basis of the bit data elements thus computed and output the controlsignal indicative of the data information thus computed to the controlsection 40. The step S17 goes forward to the step S18 wherein thecontrol section 40 is operated to control related constituent componentsof the wireless receiving apparatus 102 on the basis of the controlsignal indicative of the data information or output the control data tothe control signal outputting section 41, to be outputted to outsidecomponents, not shown.

[0155] As will be seen from the foregoing description, the wirelessreceiving apparatus 102 thus constructed is operative to receive themicrophone signal on the wireless microphone frequency carrying thevoice signal and the tone signal transmitted by the wireless microphonetransmission apparatus 101.

[0156] The operation of computing bit data elements forming datainformation performed by the data information computing section 39 willbe hereinlater described in detail.

[0157]FIG. 16 shows a flowchart showing the operation of computing bitdata elements forming data information performed by the data informationcomputing section 39. FIG. 17 shows voltage characteristicscorresponding to the integrals of the signal levels of the tones of thetone signal used for describing the operation of computing bit dataelements.

[0158] In the step S21, the crystal filter 37 is operated to filterthrough the tone signal from the microphone signal to output the tonesignal thus filtered to the data information computing section 39. Thedata information computing section 39 is operated to judge the whetherthe signal level of the tone signal thus filtered is within thedetectable range. If the data information computing section 39 judgesthat the signal level of the tone signal is within the detectable range,the step S22 goes directly to the step S26. If, on the other hand, thedata information computing section 39 judges that the signal level ofthe tone signal is out of the detectable range, the step S22 goesforward to the step S23 wherein the data information computing section39 is operated to judge whether any start bit element was detectedwithin a predetermined data detecting time period. If the datainformation computing section 39 judges that no start bit element wasdetected within the predetermined data detecting time period, the stepS23 goes forward to the step S24 wherein the data information computingsection 39 is operated to increment the voltage level, i.e., detectionlevel, applied to rectify the tone signal by a predetermined increasingratio. The step S24 goes forward to the step S26. If the datainformation computing section 39 judges that the start bit element wasdetected within the predetermined data detecting time period, the stepS23 goes to the step S25 wherein the data information computing section39 is operated to set a timer, not shown, for a time period required fortransmitting all of the bit data elements of the data string followingthe start bit, and not to change the detection level of the datainformation computing section 39 until the aforesaid time periodelapses.

[0159]FIG. 18 shows the operation of setting the timer. Morespecifically, in the present embodiment of the wireless receivingapparatus 102 according to the present invention, the data informationcomputing section 39 includes the integral computing section 39 a andthe data determining section 39 b. The data determining section 39 b isoperated to judge whether the data string following the start bit is a7-bit data string or a 13-bit data string by checking the bit lengthidentifier in the second bit data element of the data string upon orafter reading the second bit data element. If the data determiningsection 39 b judges that the data string following the start bit is a7-bit data string, the data determining section 39 b is operated to setthe timer, not shown, for the time period of seven bits plus 250milliseconds, and if the data determining section 39 b judges that thedata string following the start bit is a 13-bit data string, the datadetermining section 39 b is operated to set the timer, not shown, forthe time period of thirteen bits plus 250 milliseconds as shown in FIG.18.

[0160] Due to the discharging characteristics caused by the start bitelement and the low data element, the data determining section 39 bcannot continuously detect bit data elements. It takes approximately 250milliseconds until the voltage level of the data determining section 39b returns to the original level. For this reason, 250 milliseconds isadded to the time period of respective bits.

[0161] In the step S26, the data determining section 39 b is operated toselect one reference table from among a plurality of reference tables.Then step S26 goes forward to the step S27 wherein the integralcomputing section 39 a is operated to rectify the tone signal filteredthrough by the crystal filter 37 and compute the integral of the signallevels of the tones of the tone signal at predetermined integration timeintervals. This means that the integral computing section 39 a isoperated to read the voltage level of the tone signal thus rectified bymeans of an AD converter, not shown. In the present embodiment of thewireless receiving apparatus 102 according to the present invention, theintegral computing section 39 a is operated to read the voltage level atintegration time intervals of 5 milliseconds as shown in FIG. 17.

[0162] The step S27 goes forward to the step S28 wherein the datadetermining section 39 b is operated to compute differences between tworespective integrals of the signal levels of the tones of the tonesignal computed by the integral computing section 39 a, at respectivepredetermined data determining time intervals each starting at a leadingpoint and ending at a trailing point to acquire bit data elementsforming the data information on the basis of the differences. In thepresent embodiment of the wireless receiving apparatus 102 according tothe present invention, one data determining time interval is four timesof the integration time intervals, i.e., 20 milliseconds, each startingat a leading point and ending at an ending point as shown in FIG. 17.This means that the data determining section 39 b is operated tosequentially compute differences between two respective integrals of thesignal levels of the tones of the tone signal at respective datadetermining time intervals of 20 milliseconds starting at a startingpoint and ending at an ending point, and then sequentially identify bitdata elements in accordance with the respective differences.

[0163] The operation of determining bit data elements performed by thedata determining section 39 b will be hereinlater described in detail.

[0164] The data determining section 39 b is operated to sequentiallycompute the differences at the data determining time intervals of 20milliseconds, for every 10 millisecond as shown in FIG. 17. This meansthat the data determining section 39 b is operated to sequentially judgebit data elements in accordance with the respective differences computedfor 20 milliseconds using the selected reference table to generatejudging results each indicating any one of a start bit element, a lowdata element, and a high data element, for every 10 millisecond. Asdescribed hereinbefore, the time period required to transmit one bitdata element is 40 milliseconds. This leads to the fact that the datadetermining section 39 b is operated to judge each bit data element forfour times. In other words, the data determining section 39 b isoperated to generate four judging results for every bit data element asshown in FIG. 17. The data determining section 39 b is operated tosequentially determine each bit data element by selecting one judgingresult from among four respective judging results by majority as shownin FIG. 17. More specifically, the data determining section 39 b mayespecially consider second and third judging results among fourrespective judging results to determine respective bit data element.

[0165] The step S28 goes forward to the step S29 wherein the datadetermining section 39 b is operated to reconstruct bit data elementsforming the tone signal indicative of the data information, and outputthe bit data elements thus reconstructed to the control section 40.

[0166] As will be seen from the foregoing description, the wirelessreceiving apparatus 102 according to the present invention thusconstructed is operated to sequentially determine bit data elementsforming the tone signal indicative of the data information. Once a startbit element is detected, the wireless receiving apparatus 102 isoperated to detect the rest of the bit data elements following the startbit element for every 40 milliseconds. Also, the wireless receivingapparatus 102 is operated to detect the second bit data element directlyfollowing the start bit element 50 milliseconds after the detection ofthe start bit element in consideration of detection time lag.

[0167] The operation of detecting the power-off state of the wirelessmicrophone transmission apparatus 101 performed by the wirelessreceiving apparatus 102 will be described hereinlater with reference toFIG. 19.

[0168] The turn-off operation of the power switch of the wirelessmicrophone transmission apparatus 101 causes the wireless microphonetransmission apparatus 101 to cease to transmit any tone signal. Theturn-off and then immediate turn-on operation of the wireless microphonetransmission apparatus 101, on the other hand, causes the wirelessmicrophone transmission apparatus 101 to transmit a tone signal having astart bit element and a high data element. The wireless receivingapparatus 102 may misidentify the absent of the tone signal caused bythe turn-off operation as a start bit element. Accordingly, the wirelessreceiving apparatus 102 is operated to judge the turn-off operation ofthe wireless microphone transmission apparatus 101 if two continuousstart bit elements are detected.

[0169] As shown in FIG. 19, the second start bit element of the twocontinuous start bit elements generates a gentle slope in the voltagecharacteristics, thereby making it difficult for the conventionalwireless receiving apparatus to distinguish the second start bit elementdirectly following the start bit element from a low bit data element.

[0170] The present embodiment of the wireless receiving apparatus 102according to the present invention is operated to judge and determinethe second bit data element in the manner above described. In addition,the wireless receiving apparatus 102 is operated to judge the second bitdata element on the basis of a difference between the first bit dataelement and the second bit data element. The difference between twostart bit elements is slightly different from the difference between thestart bit element and the low bit data element. This means that thewireless receiving apparatus 102 is operated to detect the second bitdata element in the aforesaid two judging operations to ensure that theturn off operation of the wireless microphone transmission apparatus 101is detected. Furthermore, the reference tables include predeterminedvalues used for judging and determining the turn-off operation of thewireless microphone transmission apparatus 101.

[0171] As will be seen from the foregoing description, in the presentembodiment of the wireless communications system 100 according to thepresent invention, the wireless microphone transmission apparatus 101can transmit a radio microphone signal carrying a voice signalindicative of voice information and a tone signal indicative of datainformation to the wireless receiving apparatus 102, and the wirelessreceiving apparatus 102 can receive a radio microphone signal carrying avoice signal indicative of voice information and a tone signalindicative of data information.

[0172] In the present embodiment of the wireless receiving apparatus 102according to the present invention, the data information computingsection 39 can determine bit data elements on the basis of the integralsof the signal levels of the tones of the tone signal.

[0173] The signal level of the tone signal may fluctuate beyond thedetectable range due to, for example, the malfunction of a constituentcomponent of the wireless microphone transmission apparatus 101 or thewireless receiving apparatus 102. In the wireless receiving apparatus102 according to the present invention, the data information computingsection 39 can compensate the signal levels of the tones of the tonesignal if the signal level of the tone of the tone signal is out of thedetectable range, thereby enabling to accurately determine data bitelements.

[0174] In the present embodiment of the wireless receiving apparatus 102according to the present invention, the data information computingsection 39 is provided with a plurality of reference tables, and canselect one reference table from among the them in response to thedetected signal level, to determine the bit data elements on the basisof the integrals of the signal levels of the tones of the tone signal,using the selected reference table. Furthermore, the data informationcomputing section 39 may change the detection level in response to thedetected signal level so as to maintain the signal levels of the tonesof the tone signal to a certain level, thereby enabling to constantlydetermine bit data elements.

[0175] The present embodiment of the wireless receiving apparatus 102according to the present invention can selectively receive any one ofradio microphone signals on two frequency channels allocated to tworespective wireless microphone transmission apparatuses 101 a and 101 b.Alternatively, only one frequency channel may be allocated to thewireless receiving apparatus 102.

[0176] Moreover, three or more frequency channels may be allocated tothe wireless receiving apparatus 102. As described hereinbefore, thedecoding section 33, the band pass filter 34, the squelch circuitsection 35, the low-frequency amplifying section 36, the crystal filter37, the squelch circuit control section 38, the data informationcomputing section 39, the control section 40, and the control signaloutputting section 41 of the wireless receiving apparatus 101 must beuniquely dedicated to each frequency channel. This means that the samenumber of sets of the decoding section 33, the band pass filter 34, thesquelch circuit section 35, the low-frequency amplifying section 36, thecrystal filter 37, the squelch circuit control section 38, the datainformation computing section 39, the control section 40, and thecontrol signal outputting section 41 must be mounted in the case thatadditional one ore more frequency channels are allocated to the wirelessreceiving apparatus 102.

[0177] The present embodiment of the wireless receiving apparatus 102according to the present invention is adapted to output a voice signal.However, the wireless receiving apparatus 102 may be provided with avoice signal amplifying section 60, to enable to output the voice signalto a voice output device such as a speaker as shown in FIG. 20. In theaforesaid case, the control section 40 is adapted to control sound levelof the voice amplifying section 60.

[0178] The present embodiment of the wireless communications systemaccording to the present invention may comprise two wireless microphonetransmission apparatuses 101 a and 101 b, and two wireless receivingapparatuses 102 a and 102 b, in which the wireless microphonetransmission apparatuses 101 a and 101 b are adapted to transmit a radiomicrophone signal carrying a voice signal indicative of voiceinformation and a tone signal indicative of data information to thewireless receiving apparatuses 102 a and 102 b, respectively as shown inFIG. 20. The wireless microphone transmission apparatuses 101 a and 101b comprise respective control sections 40 a and 40 b, respective controlsignal outputting sections 41 a and 41 b, respective voice amplifyingsections 60 a and 60 b, and respective receiving sections 61 a and 61 b.The control sections 40 a and 40 b are adapted to control the soundlevel of any one of the voice amplifying sections 60 a and 60 b. Thismeans that the voice amplifying sections 60 a and 60 b are adapted toreceive a control signal from any one of the control signal outputtingsections 41 a and 41 b. The voice amplifying section 60 (60 a; 60 b)constitutes the voice signal outputting means according to the presentinvention.

[0179] Receiving sections 61 a and 61 b each comprise a high-frequencyamplifying section 30, a frequency conversion section 31, anintermediate-frequency amplifying section 32, a decoding section 33, aband pass filter 34, a squelch circuit section 35, a low-frequencyamplifying section 36, a crystal filter 37, a squelch circuit controlsection 38, and a data information computing section 39, respectively.

[0180] In the wireless communications system according to the presentinvention, the same microphone frequency channel may be allocated to atleast one microphone transmission apparatus and a plurality of specifiedwireless receiving apparatuses so that the wireless microphonetransmission apparatus can transmit a radio microphone signal on themicrophone frequency channel to the one or more specified wirelessreceiving apparatuses.

[0181] Alternately, in the wireless communications system according tothe present invention, the same frequency channel may be allocated to aplurality of wireless microphone transmission apparatus and at least onewireless receiving apparatus. The wireless receiving apparatus in thewireless communications system can receive the radio microphone signalon the frequency channel carrying the voice signal indicative of thevoice information and the tone signal indicative of the data informationsequentially transmitted by one or more wireless microphone transmissionapparatuses and the data information outputting unit can sequentiallyoutput the data information.

[0182] As will be seen from the foregoing description, thecommunications system according to the present invention comprises atransmission apparatus for transmitting a carrier communications signalcarrying a voice signal indicative of voice information and a tonesignal indicative of data information, and a receiving apparatus forreceiving a carrier communications signal carrying a voice signalindicative of voice information and a tone signal indicative of datainformation between and a receiving apparatus.

What is claimed is:
 1. A communications system for transmitting andreceiving a carrier communication signal carrying a voice signalindicative of voice information and a tone signal indicative of datainformation, comprising: transmission means for transmitting saidcarrier communication signal carrying said voice signal and said tonesignal; and receiving means for receiving said carrier communicationsignal carrying said voice signal and said tone signal transmitted bysaid transmission means, said transmission means including: a voiceinputting unit for inputting said voice information therethrough togenerate said voice signal indicative of said voice information; a datainputting unit for inputting said data information therethrough; a tonesignal generating unit for generating said tone signal indicative ofsaid data information on the basis of said data information inputted bysaid data inputting unit, said tone signal having a plurality of toneseach having a signal level and repeated at predetermined time intervals;a mixing unit for mixing said voice signal generated by said voiceinputting unit and said tone signal generated by said tone signalgenerating unit to generate a communication signal carrying said voicesignal and said tone signal; a modulating unit for modulating saidcommunication signal carrying said voice signal and said tone signalgenerated by said mixing unit with a carrier signal to generate acarrier communication signal carrying said voice signal and said tonesignal; a transmission unit for transmitting said carrier communicationsignal carrying said voice signal indicative of said voice informationand said tone signal indicative of said data information modulated bysaid modulating unit, therethrough, and said receiving means including:a receiving unit for receiving said carrier communication signalcarrying said voice signal indicative of said voice information and saidtone signal indicative of said data information transmitted by saidtransmission means; a demodulating unit for demodulating said carriercommunication signal carrying said voice information and said tonesignal received by said receiving unit to generate said communicationsignal; a voice signal filtering unit for filtering said voice signalindicative of said voice information therethrough from saidcommunication signal generated by said demodulating unit; a tone signalfiltering unit for filtering said tone signal therethrough from saidcommunication signal generated by said demodulating unit; an integralcomputing unit for sequentially computing integrals of said signallevels of said tones of said tone signal passed through by said tonesignal filtering unit, at first predetermined time intervals; a datainformation computing unit for sequentially computing differencesbetween two respective integrals of said signal levels of said tones ofsaid tone signal computed by said integral computing unit, at respectivesecond predetermined time intervals each starting at a leading point andending at a trailing point to acquire said data information on the basisof said differences; a data information outputting unit for outputtingsaid data information acquired by said data information computing unit,therethrough; and a voice information outputting unit for outputtingsaid voice information on the basis of said voice signal filteredthrough by said voice signal filtering unit, therethrough, in accordancewith said data information outputted by said data information outputtingunit.
 2. A communications system as set forth in claim 1, in which saiddata information computing unit of said receiving means is operative tojudge whether said integrals of said signal levels of said tones of saidtone signal computed by said integral computing unit are in apredetermined detectable range, and if said data information computingunit judges that said integrals of said signal levels of said tones ofsaid tone signal are not in said predetermined detectable range, saiddata information computing unit is operative to instruct said integralcomputing unit of said receiving means to compensate said integrals thuscomputed so that said integrals thus compensated are in saidpredetermined detectable range, and said data information computing unitis operative to sequentially compute differences between two respectiveintegrals of said signal levels of said tones of said tone signalcompensated by said integral computing unit, at respective secondpredetermined time intervals each starting at a leading point and endingat a trailing point to acquire said data information on the basis ofsaid differences.
 3. A communication method for transmitting andreceiving a carrier communication signal carrying a voice signalindicative of voice information and a tone signal indicative of datainformation, comprising the steps of: (a) transmitting said carriercommunication signal carrying said voice signal and said tone signal;and (b) receiving said carrier communication signal carrying said voicesignal and said tone signal transmitted in said step (a), said step (a)including the steps of: (a1) inputting said voice informationtherethrough to generate said voice signal indicative of said voiceinformation; (a2) inputting said data information therethrough; (a3)generating said tone signal indicative of said data information on thebasis of said data information inputted in said step (a2), said tonesignal having a plurality of tones each having a signal level andrepeated at predetermined time intervals; (a4) mixing said voice signalgenerated in said step (a1) and said tone signal generated by said step(a3) to generate a communication signal carrying said voice signal andsaid tone signal; (a5) modulating said communication signal carryingsaid voice signal and said tone signal generated in said step (a4) witha carrier signal to generate a carrier communication signal carryingsaid voice signal and said tone signal; (a6) transmitting said cariercommunication signal carrying said voice signal indicative of said voiceinformation and said tone signal indicative of said data informationmodulated in said step (a5), therethrough, and said step (b) includingthe steps of: (b1) receiving said carrier communication signal carryingsaid voice signal indicative of said voice information and said tonesignal indicative of said data information transmitted in said step (a);(b2) demodulating said carrier communication signal carrying said voiceinformation and said tone signal received in said step (b1) to generatesaid communication signal; (b3) filtering said voice signal indicativeof said voice information therethrough from said communication signalgenerated in said step (b2); (b4) filtering said tone signaltherethrough from said communication signal generated in said step (b2);(b5) sequentially computing integrals of said signal levels of saidtones of said tone signal passed through in said step (b4), at firstpredetermined time intervals; (b6) sequentially computing differencesbetween two respective integrals of said signal levels of said tones ofsaid tone signal computed in said step (b5), at respective secondpredetermined time intervals each starting at a leading point and endingat a trailing point to acquire said data information on the basis ofsaid differences; (b7) outputting said data information acquired by saidstep (b6), therethrough; and (b8) outputting said voice information onthe basis of said voice signal filtered through in said step (b3),therethrough, in accordance with said data information outputted in saidstep (b7).
 4. A communication method as set forth in claim 3, in whichsaid step (b6) has the step of (b61) judging whether said integrals ofsaid signal levels of said tones of said tone signal computed by said(b5) are in a predetermined detectable range, and if it is judged thatsaid integrals of said signal levels of said tones of said tone signalare not in said predetermined detectable range in the step (b61), saidstep (b5) has the step of (b51) compensating said integrals thuscomputed so that said integrals thus compensated are in saidpredetermined detectable range, and said step (b6) has the step of (b62)sequentially compute differences between two respective integrals ofsaid signal levels of said tones of said tone signal compensated by said(b51), at respective second predetermined time intervals each startingat a leading point and ending at a trailing point to acquire said datainformation on the basis of said differences.
 5. A wirelesscommunications system for transmitting and receiving a radio microphonesignal carrying a voice signal indicative of voice information and atone signal indicative of data information, comprising: at least onewireless microphone transmission apparatus for transmitting said radiomicrophone signal on a predetermined wireless microphone frequencychannel carrying said voice signal and said tone signal; and onewireless receiving apparatus for receiving said radio microphone signalon said predetermined wireless microphone frequency channel carryingsaid voice signal and said tone signal transmitted by said wirelessmicrophone transmission apparatus, said wireless microphone frequencychannel allocated to each of said wireless microphone transmissionapparatuses and said wireless receiving apparatus; said wirelessmicrophone transmission apparatus including: a voice inputting unit forinputting said voice information therethrough to generate said voicesignal indicative of said voice information; a data inputting unit forinputting said data information therethrough; a tone signal generatingunit for generating said tone signal indicative of said data informationon the basis of said data information inputted by said data inputtingunit, said tone signal having a plurality of tones each having a signallevel and repeated at predetermined time intervals; a mixing unit formixing said voice signal generated by said voice inputting unit and saidtone signal generated by said tone signal generating unit to generate amicrophone signal carrying said voice signal and said tone signal; amodulating unit for modulating said microphone signal on saidpredetermined wireless microphone frequency channel carrying said voicesignal and said tone signal generated by said mixing unit with a carriersignal to generate said radio microphone signal on said predeterminedwireless microphone frequency channel carrying said voice signal andsaid tone signal; a transmission unit for transmitting said radiomicrophone signal on said predetermined wireless microphone frequencychannel carrying said voice signal indicative of said voice informationand said tone signal indicative of said data information modulated bysaid modulating unit, therethrough, and said wireless receivingapparatus including: a receiving unit for receiving said radiomicrophone signal on said predetermined wireless microphone frequencychannel carrying said voice signal indicative of said voice informationand said tone signal indicative of said data information transmitted bysaid wireless microphone transmission apparatus; a demodulating unit fordemodulating said radio microphone signal on said predetermined wirelessmicrophone frequency channel carrying said voice information and saidtone signal received by said receiving unit to generate said microphonesignal; a voice signal filtering unit for filtering said voice signalindicative of said voice information therethrough from said microphonesignal generated by said demodulating unit; a tone signal filtering unitfor filtering said tone signal therethrough from said microphone signalgenerated by said demodulating unit; an integral computing unit forsequentially computing integrals of said signal levels of said tones ofsaid tone signal passed through by said tone signal filtering unit, atfirst predetermined time intervals; a data information computing unitfor sequentially computing differences between two respective integralsof said signal levels of said tones of said tone signal computed by saidintegral computing unit, at respective second predetermined timeintervals each starting at a leading point and ending at a trailingpoint to acquire said data information on the basis of said differences;a data information outputting unit for outputting said data informationacquired by said data information computing unit, therethrough; and avoice information outputting unit for outputting said voice informationon the basis of said voice signal filtered through by said voice signalfiltering unit, therethrough, in accordance with said data informationoutputted by said data information outputting unit.
 6. A wirelesscommunications system for transmitting and receiving a radio microphonesignal carrying a voice signal indicative of voice information and atone signal indicative of data information, comprising: at least onewireless microphone transmission apparatus for transmitting said radiomicrophone signal on a predetermined wireless microphone frequencychannel carrying said voice signal and said tone signal; and a pluralityof wireless receiving apparatuses for receiving said radio microphonesignal on said predetermined wireless microphone frequency channelcarrying said voice signal and said tone signal transmitted by saidwireless microphone transmission apparatus, said wireless microphonefrequency channel allocated to each of said wireless microphonetransmission apparatuses and said wireless receiving apparatuses, saidwireless microphone transmission apparatus operative to transmit saidradio microphone signal on said predetermined wireless microphonefrequency channel to one or more specified wireless receivingapparatuses including: a voice inputting unit for inputting said voiceinformation therethrough to generate said voice signal indicative ofsaid voice information; a data inputting unit for inputting said datainformation therethrough; a tone signal generating unit for generatingsaid tone signal indicative of said data information on the basis ofsaid data information inputted by said data inputting unit, said tonesignal having a plurality of tones each having a signal level andrepeated at predetermined time intervals; a mixing unit for mixing saidvoice signal generated by said voice inputting unit and said tone signalgenerated by said tone signal generating unit to generate a microphonesignal carrying said voice signal and said tone signal; a modulatingunit for modulating said microphone signal carrying said voice signaland said tone signal generated by said mixing unit with a carrier signalto generate said radio microphone signal on said predetermined wirelessmicrophone frequency channel carrying said voice signal and said tonesignal; a transmission unit for transmitting said radio microphonesignal on said predetermined wireless microphone frequency channelcarrying said voice signal indicative of said voice information and saidtone signal indicative of said data information modulated by saidmodulating unit, therethrough, and said wireless receiving apparatusincluding: a receiving unit for receiving said radio microphone signalon said predetermined wireless microphone frequency channel carryingsaid voice signal indicative of said voice information and said tonesignal indicative of said data information transmitted by said wirelessmicrophone transmission apparatus; a demodulating unit for demodulatingsaid radio microphone signal on said predetermined wireless microphonefrequency channel carrying said voice information and said tone signalreceived by said receiving unit to generate said microphone signal; avoice signal filtering unit for filtering said voice signal indicativeof said voice information therethrough from said microphone signalgenerated by said demodulating unit; a tone signal filtering unit forfiltering said tone signal therethrough from said microphone signalgenerated by said demodulating unit; an integral computing unit forsequentially computing integrals of said signal levels of said tones ofsaid tone signal passed through by said tone signal filtering unit, atfirst predetermined time intervals; a data information computing unitfor sequentially computing differences between two respective integralsof said signal levels of said tones of said tone signal computed by saidintegral computing unit, at respective second predetermined timeintervals each starting at a leading point and ending at a trailingpoint to acquire said data information on the basis of said differences;a data information outputting unit for outputting said data informationacquired by said data information computing unit, therethrough; and avoice information outputting unit for outputting said voice informationon the basis of said voice signal filtered through by said voice signalfiltering unit, therethrough, in accordance with said data informationoutputted by said data information outputting unit.
 7. A wirelesscommunications system as set forth in claim 5 or claim 6, in which saiddata information computing unit of said wireless receiving apparatus isoperative to judge whether said integrals of said signal levels of saidtones of said tone signal computed by said integral computing unit arein a predetermined detectable range, and if said data informationcomputing unit judges that said integrals of said signal levels of saidtones of said tone signal are not in said predetermined detectablerange, said data information computing unit is operative to instructsaid integral computing unit of said wireless receiving apparatus tocompensate said integrals thus computed so that said integrals thuscompensated are in said predetermined detectable range, and said datainformation computing unit is operative to sequentially computedifferences between two respective integrals of said signal levels ofsaid tones of said tone signal compensated by said integral computingunit, at respective second predetermined time intervals each starting ata leading point and ending at a trailing point to acquire said datainformation on the basis of said differences.
 8. A wirelesscommunications system as set forth in claim 5 or claim 6, in which saiddata information includes sound level control data information, saiddata inputting unit of said wireless microphone transmission apparatusis equipped with a sound level control unit for inputting said soundlevel control data information therethrough, said data tone signalgenerating unit of said wireless microphone transmission apparatus isoperative to generate a tone signal indicative of said data informationincluding said sound level control data information, said wirelessreceiving apparatus is operative to receive said radio microphone signalon said predetermined wireless microphone frequency channel carryingsaid voice signal indicative of said voice information and said tonesignal indicative of said data information including said sound levelcontrol data information transmitted by said wireless microphonetransmission apparatus, and said data information outputting unit ofsaid wireless receiving apparatus is operative to output said datainformation including said sound level control data information.
 9. Awireless communications system as set forth in claim 5 or claim 6, inwhich said data information includes a plurality of control datainformation elements, said data inputting unit of said wirelessmicrophone transmission apparatus is equipped with a plurality ofoperation switches each for inputting said control data informationelement therethrough in accordance with an operation mode, and a modeselection switch for inputting mode information therethrough to selectsaid operation mode from among a plurality of operation modes on thebasis of said mode information, said data tone signal generating unit ofsaid wireless microphone transmission apparatus is operative to generatea tone signal indicative of said data information including said controldata information elements inputted by said operation switch, saidwireless receiving apparatus is operative to receive said radiomicrophone signal on said predetermined wireless microphone frequencychannel carrying said voice signal indicative of said voice informationand said tone signal indicative of said data information including saidcontrol data information element transmitted by said wireless microphonetransmission apparatus, and said data information outputting unit ofsaid wireless receiving apparatus is operative to output said datainformation including said control data information element.
 10. Awireless communications system as set forth in claim 5 or claim 6, inwhich said wireless receiving apparatus is operative to receive saidradio microphone signal on said predetermined wireless microphonefrequency channel carrying said voice signal indicative of said voiceinformation and said tone signal indicative of said data informationincluding said sound level control data information sequentiallytransmitted by one or more wireless microphone transmission apparatuses,and said data information outputting unit of said wireless receivingapparatus is operative to sequentially output said data informationincluding said sound level control data information.
 11. A wirelesscommunications system as set forth in claim 5 or claim 6, furthercomprising an audio system electrically connected with said wirelessreceiving apparatus, in which said data information includes audiosystem control data, said data information outputting unit of saidwireless receiving apparatus is operative to output said audio systemcontrol data to said audio system, said voice information outputtingunit of said wireless receiving apparatus is operative to output saidvoice information to said audio system, and said audio system isoperative to operate in accordance with said audio system control data.12. A wireless communications system as set forth in claim 5 or claim 6,further comprising an audio-visual system electrically connected withsaid wireless receiving apparatus, in which said data informationincludes audio-visual system control data, said data informationoutputting unit of said wireless receiving apparatus is operative tooutput said audio-visual system control data to said audio-visualsystem, said voice information outputting unit of said wirelessreceiving apparatus is operative to output said voice information tosaid audio-visual system, and said audio-visual system is operative tooperate in accordance with said audio-visual system control data.
 13. Awireless communications system as set forth in claim 5 or claim 6, inwhich said data information outputting unit of said wireless receivingapparatus is capable of being electrically connected with an externaldevice and outputting said data information to said external device. 14.A wireless communications system as set forth in claim 5 or claim 6, inwhich said voice information outputting unit of said wireless receivingapparatus is capable of being electrically connected with an externaldevice and outputting said voice information to said external device.15. A wireless microphone transmission apparatus for transmitting aradio microphone signal on a predetermined wireless microphone frequencychannel carrying a voice signal indicative of voice information and atone signal indicative of data information, comprising: a voiceinputting unit for inputting said voice information therethrough togenerate said voice signal indicative of said voice information; a datainputting unit for inputting said data information therethrough; a tonesignal generating unit for generating said tone signal indicative ofsaid data information on the basis of said data information inputted bysaid data inputting unit, said tone signal having a plurality of toneseach having a signal level and repeated at predetermined time intervals;a mixing unit for mixing said voice signal generated by said voiceinputting unit and said tone signal generated by said tone signalgenerating unit to generate a microphone signal carrying said voicesignal and said tone signal; a modulating unit for modulating saidmicrophone signal carrying said voice signal and said tone signalgenerated by said mixing unit with a carrier signal to generate saidradio microphone signal on said predetermined wireless microphonefrequency channel carrying said voice signal and said tone signal; and atransmission unit for transmitting said radio microphone signal on saidpredetermined wireless microphone frequency channel carrying said voicesignal indicative of said voice information and said tone signalindicative of said data information modulated by said modulating unit,therethrough.
 16. A wireless microphone transmission apparatus as setforth in claim 15, in which said wireless microphone transmissionapparatus is operative to transmit said radio microphone signal on saidpredetermined wireless microphone frequency channel to one or morespecified wireless receiving apparatuses.
 17. A wireless microphonetransmission apparatus as set forth in claim 15, in which said datainformation includes sound level control data information, said datainputting unit is equipped with a sound level control unit for inputtingsaid sound level control data information therethrough, said data tonesignal generating unit is operative to generate a tone signal indicativeof said data information including said sound level control datainformation.
 18. A wireless microphone transmission apparatus as setforth in claim 15, in which said data information includes a pluralityof control data information elements, said data inputting unit isequipped with a plurality of operation switches each for inputting saidcontrol data information element therethrough in accordance with anoperation mode, and a mode selection switch for inputting modeinformation therethrough to select said operation mode from among aplurality of operation modes on the basis of said mode information, saiddata tone signal generating unit is operative to generate a tone signalindicative of said data information including said control datainformation elements inputted by said operation switch.
 19. A wirelessreceiving apparatus for receiving a radio microphone signal on apredetermined wireless microphone frequency channel carrying a voicesignal indicative of voice information and a tone signal indicative ofdata information, comprising: a receiving unit for receiving said radiomicrophone signal on said predetermined wireless microphone frequencychannel carrying said voice signal indicative of said voice informationand said tone signal indicative of said data information; a demodulatingunit for demodulating said radio microphone signal on said predeterminedwireless microphone frequency channel carrying said voice informationand said tone signal received by said receiving unit to generate saidmicrophone signal; a voice signal filtering unit for filtering saidvoice signal indicative of said voice information therethrough from saidmicrophone signal generated by said demodulating unit; a tone signalfiltering unit for filtering said tone signal therethrough from saidmicrophone signal generated by said demodulating unit; an integralcomputing unit for sequentially computing integrals of said signallevels of said tones of said tone signal passed through by said tonesignal filtering unit, at first predetermined time intervals; a datainformation computing unit for sequentially computing differencesbetween two respective integrals of said signal levels of said tones ofsaid tone signal computed by said integral computing unit, at respectivesecond predetermined time intervals each starting at a leading point andending at a trailing point to acquire said data information on the basisof said differences; a data information outputting unit for outputtingsaid data information acquired by said data information computing unit,therethrough; and a voice information outputting unit for outputtingsaid voice information on the basis of said voice signal filteredthrough by said voice signal filtering unit, therethrough, in accordancewith said data information outputted by said data information outputtingunit.
 20. A wireless receiving apparatus as set forth in claim 19, inwhich said data information computing unit is operative to judge whethersaid integrals of said signal levels of said tones of said tone signalcomputed by said integral computing unit are in a predetermineddetectable range, and if said data information computing unit judgesthat said integrals of said signal levels of said tones of said tonesignal are not in said predetermined detectable range, said datainformation computing unit is operative to instruct said integralcomputing unit to compensate said integrals thus computed so that saidintegrals thus compensated are in said predetermined detectable range,and said data information computing unit is operative to sequentiallycompute differences between two respective integrals of said signallevels of said tones of said tone signal compensated by said integralcomputing unit, at respective second predetermined time intervals eachstarting at a leading point and ending at a trailing point to acquiresaid data information on the basis of said differences.
 21. A wirelessreceiving apparatus as set forth in claim 19, in which said receivingunit is operative to receive said radio microphone signal on saidpredetermined wireless microphone frequency channel carrying said voicesignal indicative of said voice information and said tone signalindicative of said data information sequentially transmitted by one ormore wireless microphone transmission apparatuses, and said datainformation outputting unit is operative to sequentially output saiddata information.
 22. A wireless receiving apparatus as set forth inclaim 19, further comprising a terminal to be electrically connectablewith an audio system, said data information including audio systemcontrol data, said data information outputting unit operative to outputsaid audio system control data to said audio system, and said voiceinformation outputting unit operative to output said voice informationto said audio system.
 23. A wireless receiving apparatus as set forth inclaim 19, further comprising a terminal to be electrically connectablewith an audio-visual system, said data information includingaudio-visual system control data, said data information outputting unitoperative to output said audio-visual system control data to saidaudio-visual system, and said voice information outputting unitoperative to output said voice information to said audio-visual system.24. A wireless receiving apparatus as set forth in claim 19, in whichsaid data information outputting unit is capable of being electricallyconnected with an external device and outputting said data informationto said external device.
 25. A wireless receiving apparatus as set forthin claim 19, in which said voice information outputting unit is capableof being electrically connected with an external device and outputtingsaid voice information to said external device.